Edgar Filing: CALAMOS GLOBAL TOTAL RETURN FUND

nvcsr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED
MANAGEMENT INVESTMENT COMPANIES

INVESTMENT COMPANY ACT FILE NUMBER: 811-21547


EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER:		Calamos Global Total Return Fund


ADDRESS OF PRINCIPAL EXECUTIVE OFFICES:		2020 Calamos Court, Naperville,
		Illinois 60563-2787

NAME AND ADDRESS OF AGENT FOR SERVICE:		John P. Calamos, Sr., President
		Calamos Advisors LLC
		2020 Calamos Court
		Naperville, Illinois
		60563-2787

REGISTRANT’S TELEPHONE NUMBER, INCLUDING AREA CODE: (630) 245-7200

DATE OF FISCAL YEAR END: October 31, 2007

DATE OF REPORTING PERIOD: November 1, 2006 through October 31, 2007

TABLE OF CONTENTS


	ITEM 1. REPORTS TO SHAREHOLDERS
	ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.
	ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.
	ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.
	ITEM 6. SCHEDULE OF INVESTMENTS
	ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED—END MANAGEMENT INVESTMENT COMPANIES.
	ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.
	ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.
	ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS
	ITEM 11. CONTROLS AND PROCEDURES.
	ITEM 12. EXHIBITS.
	SIGNATURES.
Code of Ethics
Certification
906 Certification
Exhibit 99

ITEM 1. REPORTS TO SHAREHOLDERS

Include a copy of the report transmitted to stockholders pursuant to
Rule 30e-1 under the Act (17 CFR 270.30e-1).

Managing Your Calamos Funds Investments

Calamos Investments offers several convenient means to monitor, manage and feel confident about your Calamos investment choice.

TABLE OF CONTENTS



Letter to Shareholders			1

Economic and Market Review			2

Investment Team Interview			5

Schedule of Investments			10

Statement of Assets and Liabilities			15

Statement of Operations			16

Statements of Changes In Net Assets			17

Notes to Financial Statements			18

Financial Highlights			25

Report of Independent Registered

Public Accounting Firm			26

Trustee Approval of Management Agreement			27

Tax Information			30

Trustees & Officers			31

About Closed-End Funds			33

Leverage			34

Level Rate Distribution Policy and Automatic Dividend Reinvestment Plan			35

The Calamos Investments Advantage			36

Calamos Closed-End Funds			37

PERSONAL ASSISTANCE


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Letter to Shareholders

Dear Fellow Shareholders:

Thank you for your investment in Calamos Global Total Return Fund (CGO). Enclosed is the Fund’s annual report for the year ended October 31, 2007. We welcome this opportunity to communicate with you and recommend that you carefully review this report.

I’m pleased to report that both the Fund’s market price and net asset value posted all-time highs at fiscal year-end-rising 33.84% and 38.30%, respectively, for the year. Along with these impressive gains, the Fund was able to raise its monthly distribution 26% during the year. The Fund proved its mettle this past year by catching the tailwind of a robust global equity market while mostly steering clear of the credit crisis that weighed on many closed-end funds. We believe this is a testament to our global investment approach, which combines our insights about economic conditions and broader themes with rigorous analysis of individual securities.

We encourage you to stay informed on a continual basis by visiting www.calamos.com for timely fund performance, portfolio details and market commentary. At our website, you can also sign up for e-delivery to receive important shareholder communications long before the printed copies get mailed.

Thank you for the continued confidence you have placed in our team, our investment process and Calamos Closed-End Funds. We will do our utmost to continue earning your trust and look forward to serving your long-term investment goals.

Sincerely

John P. Calamos, Sr.
Chairman, CEO and Co-CIO
Calamos Advisors LLC

This report is for informational purposes only and should not be considered investment advice.

Global Total Return Fund
Letter to Shareholders ANNUAL REPORT 1

Economic and Market Review

For the latest market and economic outlook, please visit our website at www.calamos.com and select the “Individual Investors” link.

Around the globe, markets gained good ground for the one-year period ended October 31, 2007. In the United States, stocks posted a solid return of 14.56%, as measured by the S&P 500 Index.¹International markets performed even more robustly, with the MSCI EAFE Index²climbing 25.43%. Bond markets produced more muted returns: The Lehman Brothers U.S. Aggregate Index³rose 5.38%, and the CS High Yield Index⁴climbed 7.72%. Convertible securities, which blend characteristics of stocks and bonds, landed in the middle, with the Value Line Convertible Index⁵gaining 11.05%. Against this backdrop, Calamos Global Total Return Fund returned 38.30% at net asset value.

Good global growth, corporate profitability and largely contained inflation provided ongoing support for the investment markets throughout the period. However, the economic landscape was also characterized by increasing uncertainty, a renewed appreciation for risk, and a shift in investor sentiment.

During the initial months of the reporting period, traditional growth companies remained largely overlooked by investors. Economically sensitive sectors of the market dominated. Investors seemed less interested in longer-term earnings quality and gravitated toward companies with more cyclical earnings prospects. This trend cut across the global markets, but was especially pronounced in the United States. As the period progressed, however, sentiment shifted and traditional growth companies were increasingly recognized for their stable earnings prospects and quality fundamentals.

A heightened awareness of risk served as the backdrop for this rotation to quality. In February, former Federal Reserve Chairman Alan Greenspan’s comments about a potential for recession in the United States cast the global markets into turmoil. His remarks, paired with increased concern about the U.S. housing market, prompted investors to re-evaluate risk. Signs emerged that the tide was turning to growth companies that offered better prospects for sustainable earnings.

Throughout the summer, concerns about risk mounted and uncertainty grew. Deteriorating conditions in the sub-prime mortgage market served as a catalyst for a global credit crisis. Sub-prime mortgages are home loans made to borrowers with low credit scores or high amounts of debt; these loans represent a fraction of the total mortgage market. A number of hedge funds, Wall Street players and their international counterparts were forced to reckon with their use of complex mortgage derivatives and off-balance sheet financing. Concerned by the lack of transparency in the credit markets, many participants became less willing to purchase debt instruments, particularly those linked to the sub-prime mortgage market. However, even higher-quality investments and those not directly affected by the mortgage market felt the sting of negative sentiment, although their fundamentals remained intact.

The Federal Reserve, along with other central banks, took decisive steps to maintain liquidity within the markets. The Federal Reserve, in fact, cut rates

Global Total Return Fund
2 ANNUAL REPORT Economic and Market Review

Economic and Market Review

twice, first in September and then in late October. The markets regained a degree of traction and resumed their advance, and volatility declined somewhat.

The convertible market was quite healthy during the period. Valuations have appreciated since 2006, but remain fair, and issuance trends have been favorable. The varying conditions in the markets during the reporting period underscored the benefits of convertibles. Broadly speaking, convertible securities participated in the upward movement of the equity markets, while demonstrating greater resiliency in downward markets. Convertibles tend to benefit from increased volatility, which we saw during the annual period. In the U.S. market, speculative-grade convertibles outperformed investment-grade convertibles for the one-year period. However, investment-grade issues performed more strongly during the final months of the period, as investors became more wary of credit-quality risk.

In contrast, the U.S. high-yield market was more significantly challenged by risk-averse investors reacting to spreading troubles in the credit market. During the first portion of the reporting period, investor enthusiasm for high-yield bonds was robust. High-yield securities were supported by healthy earnings, a generally positive view by investors of the U.S. economy and a historically low default rate. New issuance remained strong as borrowers took advantage of low yields and high demand from investors. Conditions changed abruptly in June as losses from sub-prime mortgage securities mounted. High-yield bonds came under considerable pressure as investors fled the sector in favor of government bonds and other high-quality securities.

For the one-year period overall, CCC rated bonds performed better than higher-rated, high-yield securities. However, the higher-rated tiers of the high-yield universe gained traction as the troubles in the sub-prime market rippled across the credit markets. Within the broad high-yield market, utilities and health care sectors led for the period and financials lagged.

At the close of the period, investors found themselves confronted by mixed data. In the United States, the housing market continues to languish, but this correction was not wholly unexpected. The Federal Reserve and other central banks responded proactively to the potential liquidity issues created by the credit crisis, but the magnitude and duration of the crisis is not yet fully known and will likely take many months to work its way fully through the economy. Energy prices continue to cast a shadow and have exacerbated uncertainty about future consumer spending. However, a rising equity market and robust exports should help offset declining home values and support ongoing spending.

Although the near-term view may be more uncertain, we continue to have a favorable long-term outlook on the U.S. economy and the global economy. As we have discussed in our previous communications with shareholders, the strength of the U.S. economy is due in large measure to its diversification. Although the travails of the housing and automotive sectors have dominated the news, these

Global Total Return Fund
Economic and Market Review ANNUAL REPORT 3

Economic and Market Review

sectors are a relatively small slice of the U.S. economy, and it’s important to remember that the U.S. economy has weathered many industry-specific recessions without falling into broader recessions. Additionally, while gross domestic product (GDP) growth has declined from recovery levels, GDP growth has been respectable over recent quarters. Inflation remains contained, corporate balance sheets are still sound, and productivity and labor data are favorable. Moreover, the United States is a participant in a dynamic and growing global economy and that the strength of the global economy underpins our longer-term optimism.

Risk and uncertainty may be troubling concepts for many investors. However, three decades of experience in the markets underscores our belief that these conditions do not preclude long-term investment opportunity; rather, they provide a context for it. Our investment process seeks to understand and manage risk to create long-term wealth. Throughout the reporting period, this approach served the Fund shareholders in good stead, and we believe the Fund is advantageously positioned for what lies ahead.


¹		The S&P 500 Index is an unmanaged index generally considered representative of the U.S. stock market. Source: Lipper, Inc.

²		The MSCI EAFE^{^®}Index measures developed market equity performance (excluding the U.S. and Canada). Source: Lipper, Inc.

³		Lehman Brothers U.S. Aggregate Index, considered generally representative of the investment-grade bond market. Source: Lipper, Inc.

⁴		The CS High Yield Index is an unmanaged index of high yield debt securities. Source: Russell/Mellon Analytical Services LLC.

⁵		The Value Line Convertible Index is an equally weighted index of the larger convertibles, representing 90% of the U.S. convertible securities market. Source: Russell/Mellon Analytical Services LLC.

This report is presented for informational purposes only and should not be considered investment advice.

Global Total Return Fund
4 ANNUAL REPORT Economic and Market Review

Investment Team Interview

The Calamos Investment Management Team, led by Co-Chief Investment Officers John P. Calamos, Sr. and Nick P. Calamos, CFA, discusses the Fund’s performance, strategy and positioning during the one-year period ended October 31, 2007.

TOTAL RETURN*

Common Shares — Inception 10/27/05


				Since
	1 Year			Inception**
On Market Price		33.84	%		21.28	%
On NAV		38.30	%		28.86	%


*		Total return measures net investment income and capital gain or loss from portfolio investments, assuming reinvestment of income and capital gains distributions.

**		Annualized since inception.

Q. How did the Fund perform during the reporting period?

A. Calamos Global Total Return Fund (CGO) provided investors with a strong return that surpassed the MSCI World Index¹by a wide margin. The Fund’s underlying portfolio (as represented by net asset value, or NAV) returned 38.30% for the one-year period. On a market price basis, the Fund returned 33.84% assuming reinvestment of distributions. In contrast, the MSCI World Index gained 20.97%.

The Fund also raised its monthly distribution twice during the reporting period. (See “Distribution History” table.) Particularly given the challenging market environment, we are pleased to have provided shareholders with this wide margin of outperformance as well as an increased income stream. We believe the Fund’s performance underscores the benefits of our dynamic asset allocation and rigorous proprietary research.

Q. What’s the difference between market return and NAV return?

A. Closed-end funds trade on exchanges, where the price of a share may be driven by factors other than the value of the underlying securities. The price of a share in the market is called the market value. The market price may be influenced by factors that are unrelated to the performance of the Fund’s holdings. For example, the market price may reflect investor sentiment or anxiety about certain parts of the market. During the reporting period, for example, problems in certain sectors of

DISTRIBUTION HISTORY (LATEST 12 MONTHS)


Date Paid	Per share
October	$	0.1100
September		0.1100
August		0.1100
July		0.1100
June		0.1100
May		0.1100
April		0.0975
March		0.0975
February		0.0875
January		0.0875
December		0.0875
November		0.0875

Monthly distributions are from net investment income, short-term capital gains and/or long-term capital gains. For more details please go to the Tax Center located at www.calamos.com.

the bond markets (most notably, the mortgage market) created a cloud of negative sentiment that extended across much broader sections of the credit market.

Global Total Return Fund
Investment Team Interview ANNUAL REPORT 5

Investment Team Interview

QUALITY ALLOCATION


Weighted Average Credit Quality	BBB -
AAA		7.1	%
AA		1.1
A		5.8
BBB		8.7
BB		19.5
B		30.7
CCC or below		7.2
Not Rated		19.9

Data is based on a portion of portfolio holdings. Credit quality shown reflects the higher of the ratings of Standard & Poor’s Corporation or Moody’s Investors Service, Inc. Ratings are relative, subjective and not absolute standards of quality. Excludes equity securities, options, cash and short-term investments.

REGIONAL ALLOCATION


North America	41.0	%
Europe	31.5
Asia Pacific	23.9
Latin America	2.6
Middle East / Africa	0.9
Caribbean	0.1

Region allocations are based on portfolio holdings.

We believe NAV returns are the more appropriate measure of a manager’s performance. The Fund’s NAV return measures the return of the individual securities within the portfolio, less Fund expenses, but more importantly, it is a measure of how well the manager is able to avoid or capitalize on market disruptions or opportunities. The higher the return, the more value the Fund’s management team added through its security selection decisions.

Q. As of the close of the period, the Fund traded at a discount of 7.32%. In your opinion, how should investors view this discount?

A. A discount reflects market sentiment, which can be influenced by many factors unrelated to the performance of the Fund. Accordingly, we believe discounts are best evaluated within a broader context. During the past year, for example, CGO outperformed the MSCI World Index by a wide margin, and provided increasing income—while trading at a discount. Additionally, we note that a discount affords investors the opportunity to buy shares at a price that is lower than the fair value of the portfolio (as measured by NAV).

Q. In the Economic and Market Review, you explained that sub-prime mortgages and certain types of debt linked to the mortgage market fell steeply. Did the Fund invest in those types of securities?

A. The Fund did not invest in securities backed by sub-prime loans, including collateralized debt instruments and structured investment vehicles. These were the areas that came under the greatest pressure during the summer sell off. Collateralized debt obligations are complex securities that represent an interest in pools of securities backed by mortgages, bonds, loans and other financial instruments. Structured investment vehicles are funded by debt; they profit by purchasing securities yielding more than the cost of capital.

We believed such areas of the market represented an undue level of risk and were concerned by their lack of transparency. This prudence served the Fund well during the period.

Q. Before you discuss the specific factors that influenced performance, how did you position the Fund during the period?

A. This Fund invests across asset classes, including common stocks, convertible securities and corporate bonds. We adjust the allocation based on our view of the economic landscape as well as the opportunity potential of individual securities. As of the close of the period, the Fund held the majority of its assets in common stocks, reflecting our positive outlook on the equity markets.

Convertible securities represented approximately 21% of the portfolio at the close of the reporting period, roughly the same as the allocation to corporate bonds. We

Global Total Return Fund
6 ANNUAL REPORT Investment Team Interview

Investment Team Interview

SECTOR ALLOCATION


Information Technology	20.4	%
Consumer Discretionary	19.6
Financials	15.3
Health Care	10.5
Consumer Staples	10.3
Energy	6.2
Materials	4.8
Telecommunication Services	4.7
Industrials	3.9
Sovereign Bonds	2.5
Utilities	1.4

Sector allocations are based on managed assets and may vary over time.

COUNTRY ALLOCATION


United States	38.3	%
Japan	7.4
United Kingdom	7.3
Australia	7.1
Switzerland	5.6
Singapore	4.5
Finland	4.0
Germany	3.4
Bermuda	3.0
Other Combined	19.4

Country allocation is based on portfolio holdings.

utilized convertible securities to provide downside protection as well as income. Convertible securities offer the potential for upside appreciation in rising equity markets and potential downside protection in declining markets. They also typically benefit from increased equity market volatility.

This Fund has the flexibility to invest across the global markets. Although the United States represents the Fund’s single largest country allocation, the Fund is underweighted in the United States relative to the MSCI World Index. This reflects our view on the potential slowdown of the U.S. economy versus the higher growth opportunity in non-U.S. markets. Overall, our positioning favors developed markets in Asia and Europe. Our investment process favors countries that espouse free market principles and economic freedoms, such as private property rights, transparent accounting practices and credible rule of law.

From a sector standpoint, we are favoring companies from traditional growth sectors, such as information technology. For many quarters, we have been concerned about companies whose prospects are tied primarily to recovery-level economic growth or commodity prices. We sought companies with sustainable earnings growth potential, good balance sheets and cash flows, high return on invested capital, reliable debt servicing and significant revenue exposure to non-U.S. economies. In contrast, the Fund holds smaller stakes in economically sensitive sectors such as materials, energy and industrials.

While we focus on delivering steady income to shareholders, we view this income as a component of total return. We carefully evaluate yield opportunity within the context of potential risk. The Fund’s corporate and convertible holdings are diversified across the credit spectrum. We are particularly cautious in regards to the lowest tiers of the credit spectrum, reflecting our belief that a higher income stream cannot make up for a default.

Q. What factors enhanced performance?

A. The Fund was well served by security selection in the financials sector. Our investment process includes a thematic component. That is, we seek companies that will benefit from long-term societal trends, such as increased pension investing in Europe and the expansion of well regulated stock exchanges around the world. During the period, stock exchanges, insurers and re-insurers and investment banking and brokerages enhanced performance. Moreover, as the broad financials sector was buffeted by headwinds as the credit crunch unfolded, an underweighting to the overall sector helped performance.

The Fund benefited from its holdings in the information technology sector as well as from its overweight to the sector versus the MSCI World Index. Here again, our thematic approach led us to strong performers. For example, we believe the competitive nature of the global economy will encourage companies to make significant investments in productivity enhancers, which in turn should benefit

Global Total Return Fund
Investment Team Interview ANNUAL REPORT 7

Investment Team Interview

technology companies. Also, we believe information technology companies are advantageously positioned to capitalize on consumers’ desire to be connected to information, entertainment and each other. Leading contributors to performance tapped into both of these themes. Security selection in energy and industrials also contributed favorably to performance.

Q. What factors hindered performance?

A. Compared with the MSCI World Index, the Fund was underweighted in the materials sector, an area that performed strongly within the index. An overweighting to consumer discretionary relative to the index also slowed the Fund’s relative performance.

Q. Please explain how the Fund employs leverage and how the Fund’s leverage strategy contributed to performance.

A. Leverage strategies continued to contribute favorably to the returns earned by the Fund’s common shareholders despite the turmoil in the credit markets. Leverage strategies typically entail borrowing at short-term interest rates and investing the proceeds at higher rates of return.

Because of the turmoil in the credit market, many investors have a heightened apprehension about strategies that employ leverage. During the reporting period, concerns about creditworthiness cut a wide swath in the credit market. For a time, even the short-term, high-quality market came under pressure. In this environment, the cost of the Fund’s leverage increased. However, as the period progressed, the cost of leverage returned to more normal levels, as investors were reassured by the Federal Reserve’s decisive moves to maintain liquidity through reductions to the discount and target rates.

Q. In a more uncertain market environment, what is your outlook for the Fund?

A. We have a high degree of conviction in the Fund’s positioning and emphasis on risk management. As the past year demonstrated, CGO’s dynamic strategy allowed Fund shareholders to receive steady income and growth in NAV—despite the rising uncertainty in the credit markets and the U.S. economy. We believe the Fund’s broad mandate provides ample opportunities for us to manage risk while enhancing returns. We are particularly optimistic about the Fund’s global focus and its ability to participate in dynamic trends in both the United States and overseas.

We believe that traditional growth sectors are most compelling in a period of less certain, but still respectable economic growth. Within the convertible market, valuations have appreciated since 2006 but remain fair, and issuance trends have been favorable. Currently, a good portion of convertibles offer what we consider optimal characteristics, that is, a good mix of upside participation and downside safety.

Global Total Return Fund
8 ANNUAL REPORT Investment Team Interview

Investment Team Interview

Our view on the broad corporate bond market is more cautious and we believe individual security selection will be particularly important. The credit crisis of the summer will take time to resolve, and many of the most speculative credits may not offer suitably high compensation for the risk they entail. However, as we discussed in the Economic and Market Review, we believe that U.S. companies are in good shape overall; this strength should provide support for the corporate bond market. We believe that opportunity remains and that our rigorous and proprietary credit research will be of considerable benefit in uncovering securities with attractive yields and reasonable risk.


¹		The MSCI World Index (U.S. dollars) is a market capitalization weighted index composed of companies representative of the market structure of developed market countries in North America, Europe and the Asia/Pacific region. Source: Lipper, Inc.

Global Total Return Fund
Investment Team Interview ANNUAL REPORT 9

Schedule of Investments

OCTOBER 31, 2007


PRINCIPAL
AMOUNT			VALUE

CORPORATE BONDS (28.3%)
		*Consumer Discretionary (14.1%)*
$	1,500,000	Asbury Automotive Group, Inc.^ 7.625%, 03/15/17	$	1,410,000
	2,060,000	DIRECTV Financing Company, Inc.~ 8.375%, 03/15/13		2,163,000
	1,000,000	Expedia, Inc.~ 7.456%, 08/15/18		1,033,693
	1,600,000	Ford Motor Company~ 9.875%, 08/10/11		1,598,811
	1,000,000	General Motors Corp.^ 7.200%, 01/15/11		960,000
	1,875,000	Goodyear Tire & Rubber Company~ 7.857%, 08/15/11		1,950,000
	2,000,000	Hanes Brands, Inc.~‡ 8.784%, 12/15/14		2,020,000
	2,000,000	Idearc, Inc.~ 8.000%, 11/15/16		2,015,000
	440,000	Jarden Corp.~ 7.500%, 05/01/17		420,200
	2,000,000	Liberty Media Corp.~ 8.250%, 02/01/30		1,976,040
	2,000,000	Mandalay Resort Group~ 7.625%, 07/15/13		1,995,000
	2,325,000	NCL Holding, ASA~ 10.625%, 07/15/14		2,365,688
	2,000,000	Royal Caribbean Cruises, Ltd.~ 7.500%, 10/15/27		1,900,012
	2,000,000	Service Corp. International~ 7.500%, 04/01/27		1,880,000

				23,687,444


		*Consumer Staples (2.1%)*
	1,500,000	Del Monte Foods Company~ 8.625%, 12/15/12		1,537,500
		Pilgrim’s Pride Corp.
	1,500,000	8.375%, 05/01/17^		1,518,750
	500,000	7.625%, 05/01/15~		505,000

				3,561,250


		*Energy (0.5%)*
	750,000	Petróleo Brasileiro, SA~ 8.375%, 12/10/18		885,000


		*Financials (0.8%)*
	500,000	E*TRADE Financial Corp.~ 7.875%, 12/01/15		460,000
	920,000	Leucadia National Corp.~ 8.125%, 09/15/15		932,650

				1,392,650


		*Health Care (1.7%)*
	1,800,000	HCA, Inc.* 9.250%, 11/15/16		1,899,000
	1,000,000	Tenet Healthcare Corp.~ 9.250%, 02/01/15		885,000

				2,784,000


		*Industrials (1.0%)*
	1,800,000	H&E Equipment Service, Inc.~ 8.375%, 07/15/16		1,755,000


		*Information Technology (2.8%)*
	900,000	Avago Technologies~ 11.875%, 12/01/15		1,012,500
	1,000,000	iPayment, Inc.~ 9.750%, 05/15/14		965,000
	2,700,000	SunGard Data Systems, Inc.~ 9.125%, 08/15/13		2,767,500

				4,745,000


		*Materials (2.6%)*
	900,000	Ineos Group Holdings, PLC* 7.875%, 02/15/16		1,205,917
	2,000,000	Mosaic Company~* 7.625%, 12/01/16		2,165,000
	1,000,000	Polyone Corp. 8.875%, 05/01/12		1,040,000

				4,410,917


		*Telecommunication Services (2.7%)*
	1,700,000	Citizens Communications Company~ 9.000%, 08/15/31		1,757,375
	2,000,000	Leap Wireless International, Inc.~ 9.375%, 11/01/14		1,995,000
	750,000	Windstream Corp.~ 8.625%, 08/01/16		806,250

				4,558,625


		TOTAL CORPORATE BONDS (Cost $47,917,608)		47,779,886


CONVERTIBLE BONDS (15.2%)
		*Consumer Discretionary (5.4%)*
	1,000,000	Amazon.com, Inc.~ 4.750%, 02/01/09		1,192,500
	1,500,000	Ford Motor Company~ 4.250%, 12/15/36		1,803,750
	1,500,000	General Motors Corp.~ 6.250% 07/15/33		1,542,000
	1,500,000	Intralot SA 2.250%, 12/20/13		2,498,747
	850,000	Punch Taverns Redwood Jersey Company Ltd. 5.000%, 12/14/10		2,047,842

				9,084,839


		*Health Care (1.1%)*
	1,700,000	Wyeth~‡ 4.886%, 01/15/24		1,822,842

See accompanying Notes to Schedule of Investments.

Global Total Return Fund
10 ANNUAL REPORT Schedule of Investments

Schedule of Investments

OCTOBER 31, 2007


PRINCIPAL
AMOUNT			VALUE

		*Industrials (2.7%)*
$	1,700,000	MTU Aero Engines Holdings, AG 2.750%, 02/01/12	$	2,699,545
	1,175,000	Quanta Services, Inc.~* 3.750%, 04/30/26		1,863,844

				4,563,389


		*Information Technology (3.6%)*
	3,300,000	Business Objects, SA 2.250%, 01/01/27		2,409,226
	2,500,000	Intel Corp.^~ 2.950%, 12/15/35		2,681,250
	900,000	VeriSign, Inc.~* 3.250%, 08/15/37		1,078,875

				6,169,351


		*Telecommunication Services (0.5%)*
	900,000	NII Holdings, Inc.* 3.125%, 06/15/12		835,875


		*Utilities (1.9%)*
	1,550,000	International Power, PLC 3.250%, 07/20/13		3,139,200


		TOTAL CONVERTIBLE BONDS (Cost $22,679,858)		25,615,496


SYNTHETIC CONVERTIBLE SECURITIES (5.1%)
*Sovereign Bonds (3.4%)*
		*Consumer Discretionary (3.4%)*
	1,800,000	Deutschland Republic Treasury 4.500%, 07/04/09		2,621,596
	1,500,000	United Kingdom Treasury 5.750%, 12/07/09		3,159,802

		TOTAL SOVEREIGN BONDS		5,781,398


NUMBER OF
CONTRACTS			VALUE

*Options (1.7%)*
		*Consumer Discretionary (0.1%)*
	65	Garmin, Ltd.# Call, 01/17/09, Strike $100.00		195,650


		*Industrials (0.2%)*
	90	Alliant Techsystems, Inc.# Call, 01/17/09, Strike $110.00		140,850
	165	Honeywell International, Inc.# Call, 01/17/09, Strike $55.00		183,150

				324,000


		*Information Technology (1.4%)*
	100	Apple, Inc.# Call, 01/17/09, Strike $130.00		752,500
	235	Cisco Systems, Inc.# Call, 01/17/09, Strike $30.00	$	166,263

	35	Google, Inc.# Call, 01/17/09, Strike $520.00		828,625
	90	Research In Motion, Ltd.# Call, 01/17/09, Strike $73.30		548,100

				2,295,488

		TOTAL OPTIONS		2,815,138


		TOTAL SYNTHETIC CONVERTIBLE SECURITIES (Cost $6,940,621)		8,596,536


NUMBER OF
SHARES			VALUE

CONVERTIBLE PREFERRED STOCKS (8.1%)
		*Financials (1.8%)*
	32,000	MetLife, Inc.~ 6.375%		1,072,640
	1,100	Swiss Re 6.000%		997,264
	20,000	Washington Mutual, Inc.~ 5.375%		885,000

				2,954,904


		*Health Care (2.5%)*
	16,000	Schering-Plough Corp.~ 6.000%		4,260,000


		*Materials (3.8%)*
	34,000	Cia Vale do Rio Doce~ 5.500%		2,489,480
	450	Givaudan SA 5.375%		3,972,851

				6,462,331


		TOTAL CONVERTIBLE PREFERRED STOCKS (Cost $13,230,138)		13,677,235


COMMON STOCKS (77.5%)
		*Consumer Discretionary (6.8%)*
	135,000	Esprit Holdings, Ltd.		2,254,678
	53,000	Hennes & Mauritz AB		3,541,429
	20,000	Industria de Diseno Textil, SA		1,495,374
	20,000	Nike, Inc.~		1,325,200
	10,000	Volkswagen, AG		2,858,583

				11,475,264


		*Consumer Staples (11.7%)*
	100,000	British American Tobacco, PLC		3,809,757
	40,000	Coca-Cola Company~		2,470,400
	44,000	Heineken, NV		3,088,679
	32,000	InBev, NV	$	3,028,713
	7,000	Nestle Holdings, Inc.		3,233,173

See accompanying Notes to Schedule of Investments.

Global Total Return Fund
Schedule of Investments ANNUAL REPORT 11

Schedule of Investments

OCTOBER 31, 2007


NUMBER OF
SHARES			VALUE

	40,000	Reynolds American, Inc.^	$	2,577,200
	50,000	Woolworths, Ltd.		1,567,083

				19,775,005


		*Energy (7.8%)*
	16,000	Canadian Natural Resources, Ltd.		1,330,609
	30,000	Chevron Corp.~		2,745,300
	30,000	ENI S.p.A.		1,095,398
	170,000	Nippon Oil Corp.		1,505,637
	24,800	PetroChina Company, Ltd.^~		6,512,480

				13,189,424


		*Financials (18.0%)*
	105,000	Australian Stock Exchange, Ltd.		5,661,884
	33,120	EFG Eurobank Ergasias		1,292,385
	7,000	Goldman Sachs Group, Inc.~		1,735,440
	380,000	Henderson Group, PLC		1,486,282
	40,000	JPMorgan Chase & Company~		1,880,000
	40,000	Manulife Financial Corp.^		1,855,600
	52,000	Power Financial Corp.		2,318,023
	135,000	QBE Insurance Group, Ltd.		4,131,345
	916,000	Singapore Exchange, Ltd.		10,037,164

				30,398,123


		*Health Care (9.0%)*
	22,000	Alcon, Inc.^~		3,348,620
	43,000	Astellas Pharma, Inc.		1,908,831
	63,000	CSL, Ltd.		2,141,753
	21,000	Johnson & Johnson~		1,368,570
	60,000	Merck & Company, Inc.~		3,495,600
	72,000	Pfizer, Inc.~		1,771,920
	6,000	Roche Holding, AG		1,024,819

				15,060,113


		*Industrials (1.4%)*
	40,000	Leighton Holdings, Ltd.		2,341,717


		*Information Technology (19.7%)*
	37,000	Canon, Inc.		1,872,178
	90,000	Infosys Technologies, Ltd.~		4,584,600
	68,000	Microsoft Corp.~		2,503,080
	13,000	Nintendo Company, Ltd.		8,256,023
	225,000	Nokia Corp.		8,935,979
	37,000	SAP, AG		2,000,720
	17,000	TDK Corp.		1,395,183
	185,000	Toshiba Corp.		1,566,632
	240,000	Vtech Holdings, Ltd.		2,049,380

				33,163,775


		*Telecommunication Services (3.1%)*
	38,000	America Movil, S.A. de C.V.~	$	2,484,820
	400,000	BT Group, PLC#		2,718,892

				5,203,712


		TOTAL COMMON STOCKS (Cost $80,851,087)		130,607,133


WARRANTS (0.1%)
		*Consumer Discretionary (0.1%)*
	36,362	Expedia, Inc.# 05/07/12, Strike $24.46 (Cost $72,179)		253,443


NUMBER OF
CONTRACTS			VALUE

PUT OPTIONS (0.3%)
		*Financials (0.3%)*
		SPDR Trust Series 1#
	1,235	Put, 03/22/08, Strike $144.00		444,600
	235	Put, 11/17/07, Strike $138.00		1,763
	230	Put, 11/07/07, Strike $137.00		1,265

		TOTAL OPTIONS (Cost $523,830)		447,628


NUMBER OF
SHARES			VALUE

INVESTMENT IN AFFILIATED FUND (1.2%)
	1,952,459	Calamos Government Money Market Fund — Class I Shares 3 4.711% (Cost $1,952,459)		1,952,459

INVESTMENTS OF CASH COLLATERAL FOR SECURITIES ON LOAN (7.9%)
	13,371,000	Bank of New York Institutional Cash Reserve Fund current rate 5.158% (Cost $13,371,000)		13,371,000

TOTAL INVESTMENTS (143.7%) (Cost $187,538,780)				242,300,816


PAYABLE UPON RETURN OF SECURITIES ON LOAN (-7.9%)				(13,371,000	)


LIABILITIES, LESS OTHER ASSETS (-0.8%)				(1,371,017	)


PREFERRED SHARES AT REDEMPTION VALUE INCLUDING DIVIDENDS PAYABLE (-35.0%)				(59,008,196	)


NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS (100.0%)			$	168,550,603

See accompanying Notes to Schedule of Investments.

Global Total Return Fund
12 ANNUAL REPORT Schedule of Investments

Schedule of Investments

OCTOBER 31, 2007


NUMBER OF
CONTRACTS			VALUE

WRITTEN OPTIONS (-1.9%)
		*Financials (-1.9%)*
		iShares MSCI EAFE Index Fund#
	1,500	Call, 12/22/07, Strike $85.00	$	(517,500	)
	1,360	Call, 12/22/07, Strike $83.00		(666,400	)
	1,350	Call, 12/22/07, Strike $84.00		(567,000	)
	1,200	Call, 03/22/08, Strike $85.00		(552,000	)
	540	Call, 12/22/07, Strike $80.00		(399,600	)
		SPDR Trust Series 1#
	400	Call, 12/22/07, Strike $158.00		(102,000	)
	250	Call, 11/17/07, Strike $159.00		(11,750	)
	115	Call, 03/22/08, Strike $152.00		(113,850	)
	100	Call, 12/22/07, Strike $157.00		(30,500	)
	100	Call, 03/22/08, Strike $150.00		(112,500	)
	85	Call, 03/22/08, Strike $157.00		(57,375	)


		TOTAL WRITTEN OPTIONS (Premium $2,344,844)		(3,130,475	)

NOTES TO SCHEDULE OF INVESTMENTS


Note: Value for Securities denominated in foreign currencies is shown in U.S. dollars. The principal amount for such securities are shown in the respective foreign currency. The date shown on options represents the expiration date of the option contract. The option contract may be exercised at any date on or before the date shown.

^		Security, or portion of security, is on loan.

~		Security, or portion of security, is held in a segregated account as collateral for written options aggregating a total market value of $86,650,848.

‡		Variable rate or step bond security. The rate shown is the rate in effect at October 31, 2007.

*		Securities issued and sold pursuant to a Rule 144A transaction are excepted from the registration requirement of the Securities Act of 1933, as amended. These securities may only be sold to qualified institutional buyers (“QIBs”), such as the Fund. Any resale of these securities must generally be effected through a sale that is registered under the Act or otherwise exempted or excepted from such registration requirements. At October 31, 2007 the value of 144A securities that could not be exchanged to the registered form is $6,348,792 or 3.8% of net assets.

#		Non-income producing security.

W		Investment in an affiliated fund. During the period from November 1, 2006, through October 31, 2007, the fund had net purchases of $1,952,459, and received $63,656 in dividend payments from the affiliated fund. As of October 31, 2006, the Fund had no holdings of the affiliated fund.

See accompanying Notes to Financial Statements.

Global Total Return Fund
Schedule of Investments ANNUAL REPORT 13

Schedule of Investments

OCTOBER 31, 2007

COUNTRY ALLOCATION AS OF OCTOBER 31, 2007


Country	% of Portfolio
United States		38.3	%
Japan		7.4
United Kingdom		7.3
Australia		7.1
Switzerland		5.6
Singapore		4.5
Finland		4.0
Germany		3.4
Bermuda		3.0
China		2.9
Canada		2.7
India		2.0
Greece		1.7
Sweden		1.6
Brazil		1.5
Netherlands		1.4
Belgium		1.3
Mexico		1.1
France		1.1
Liberia		0.8
Spain		0.7
Italy		0.5
Cayman Islands		0.1
Total:		100.0	%

Country allocations vary over time.

See accompanying Notes to Financial Statements.


14		Global Total Return Fund ANNUAL REPORT Schedule of Investments

Statement of Assets and Liabilities


October 31, 2007
ASSETS
Investments, at value* (cost $185,586,321)	$	240,348,357
Investments in affiliated fund (cost $1,952,459)		1,952,459
Cash with custodian (interest bearing)		1,134
Accrued interest and dividends receivable		2,012,157
Prepaid expenses		8,635
Other assets		17,669

Total assets		244,340,411

LIABILITIES
Options written, at value (premium $2,344,844)		3,130,475
Cash collateral for securities on loan		13,371,000
Affiliates:
Investment advisory fees		186,319
Financial accounting fees		2,130
Deferred compensation to Trustees		17,669
Trustee fees and officer compensation		257
Accounts payable and accrued liabilities		73,762

Total liabilities		16,781,612

PREFERRED SHARES
$25,000 liquidation value per share applicable to 2,360 shares, including dividends payable		59,008,196

NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS	$	168,550,603

COMPOSITION OF NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS
Common stock, no par value, unlimited shares authorized 8,006,981 shares issued and outstanding	$	113,591,761
Undistributed net investment income (loss)		(206,348	)
Accumulated net realized gain (loss) on investments, written options, and foreign currency transactions		1,166,189
Net unrealized appreciation (depreciation) on investments, written options, and foreign currency translations		53,999,001

NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS	$	168,550,603

Net asset value per common share based on 8,006,981 shares issued and outstanding	$	21.05

*Including securities on loan with a value of $13,457,659.

See accompanying Notes to Financial Statements.


Global Total Return Fund Statement of Assets and Liabilities ANNUAL REPORT			15

Statement of Operations


Year Ended October 31, 2007
INVESTMENT INCOME
Interest	$	6,068,902
Dividends (net of foreign taxes withheld of $92,485)		3,959,321
Dividends from affiliates		63,656
Securities lending income		25,793

Total investment income		10,117,672

EXPENSES
Investment advisory fees		2,016,530
Financial accounting fees		22,829
Auction agent and rating agency fees		165,167
Audit and legal fees		45,739
Custodian fees		48,366
Printing and mailing fees		42,526
Transfer agent fees		30,401
Registration fees		24,386
Trustees’ fees and officer compensation		19,851
Accounting fees		10,587
Investor support services		7,717
Other		26,182

Total expenses		2,460,281
Less expense reductions		(8,309	)

Net expenses		2,451,972

NET INVESTMENT INCOME(LOSS)		7,665,700

REALIZED AND UNREALIZED GAIN(LOSS) FROM INVESTMENTS, WRITTEN OPTIONS, AND FOREIGN CURRENCY
Net realized gain (loss) from:
Investments		9,396,512
Written options		(3,797,667	)
Foreign currency transactions		49,472
Change in net unrealized appreciation/depreciation on:
Investments		36,380,232
Written options		1,015,939
Foreign currency translations		17,564

NET REALIZED AND UNREALIZED GAIN (LOSS) FROM INVESTMENTS, WRITTEN OPTIONS, AND FOREIGN CURRENCY		43,062,052

NET INCREASE (DECREASE) IN NET ASSETS RESULTING FROM OPERATIONS		50,727,752

DISTRIBUTIONS TO PREFERRED SHAREHOLDERS FROM
Net investment income		(3,095,387	)
Capital gains		(21,448	)

NET INCREASE (DECREASE) IN NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS RESULTING FROM OPERATIONS	$	47,610,917

See accompanying Notes to Financial Statements.


16		Global Total Return Fund ANNUAL REPORT Statement of Operations

Statements of Changes in Net Assets


	Year Ended October 31,
	2007			2006

OPERATIONS
Net investment income (loss)	$	7,665,700		$	6,878,195
Net realized gain (loss) from investments, written options, and foreign currency transactions		5,648,317			2,569,858
Change in net unrealized appreciation/depreciation on investments, written options, and foreign currency translations		37,413,735			16,585,266
Distributions to preferred shareholders from:
Net investment income		(3,095,387	)		(2,331,114	)
Capital gains		(21,448	)		—

Net increase (decrease) in net assets applicable to common shareholders resulting from operations		47,610,917			23,702,205


DISTRIBUTIONS TO COMMON SHAREHOLDERS FROM
Net investment income		(8,697,994	)		(5,173,457	)
Capital gains		(950,430	)		(1,532,399	)

Net decrease in net assets from distributions to common shareholders		(9,648,424	)		(6,705,856	)


CAPITAL SHARE TRANSACTIONS
Offering costs on preferred shares		—			(847,169	)

Net increase (decrease) in net assets from capital share transactions		—			(847,169	)

TOTAL INCREASE (DECREASE) IN NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS		37,962,493			16,149,180


NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS
Beginning of year	$	130,588,110		$	114,438,930

End of year		168,550,603			130,588,110

Undistributed net investment income (loss)	$	(206,348	)	$	481,284

See accompanying Notes to Financial Statements.


Global Total Return Fund Statements of Changes in Net Assets ANNUAL REPORT			17

Notes to Financial Statements

NOTE 1 — ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES

Organization. CALAMOS Global Total Return Fund (the ''Fund’’) was organized as a Delaware statutory trust on March 30, 2004 and is registered under the Investment Company Act of 1940 (the “1940 Act”) as a diversified, closed-end management investment company. The Fund commenced operations on October 27, 2005.

The Fund’s investment objective is to provide total return through a combination of capital appreciation and current income.

Portfolio Valuation. Calamos Advisors LLC, the Fund’s investment adviser (“Calamos Advisors”), overseas the valuation of the Fund’s portfolio securities in accordance with policies and procedures on the valuation of securities adopted by and under the ultimate supervision of the Board of Trustees.

Portfolio securities that are traded on U.S. securities exchanges, except option securities, are valued at the last current reported sales price at the time as of which a Fund determines its net asset value (“NAV”). Securities traded in the over-the-counter (''OTC’’) market and quoted on The NASDAQ Stock Market are valued at the NASDAQ Official Closing Price (''NOCP’’), as determined by NASDAQ, or lacking a NOCP, the last current reported sale price on NASDAQ at the time as of which a Fund determines its NAV.

When a most recent last sale or closing price is not available, portfolio securities, other than option securities, that are traded on a U.S. securities exchange and other securities traded in the OTC market are valued at the mean between the most recent bid and asked quotations in accordance with guidelines adopted by the Board of Trustees. Each option security traded on a U.S. securities exchange is valued at the mid-point of the consolidated bid/ask quote for the option security, also in accordance with guidelines adopted by the Board of Trustees. Each OTC option that is not traded through the Options Clearing Corporation is valued based on a quotation provided by the counterparty to such option under the ultimate supervision of the Board of Trustees.

Trading in securities on European and Far Eastern securities exchanges and OTC markets is typically completed at various times before the close of business on each day on which the New York Stock Exchange (“NYSE”) is open. Each security trading on these exchanges or OTC markets is evaluated utilizing a systematic fair valuation model provided by an independent pricing service approved by the Board of Trustees. The valuation of each security that meets certain criteria in relation to the valuation model is systematically adjusted to reflect the impact of movement in the U.S. market after the foreign markets close. Securities that do not meet the criteria, or that are principally traded in other foreign markets, are valued as of the last current sale price at the time as of which the Fund determines its NAV, or when reliable market prices or quotations are not readily available, at the mean between the most recent bid and asked quotations as of the close of the appropriate exchange or other designated time, in accordance with guidelines adopted by the Board of Trustees. Trading of foreign securities may not take place on every NYSE business day. In addition, trading may take place in various foreign markets on Saturdays or on other days when the NYSE is not open and on which the Fund’s NAV is not calculated.

If the pricing committee determines that the valuation of a security in accordance with the methods described above is not reflective of a fair value for such security, the security, including any thinly-traded security, below investment grade bond or synthetic convertible instrument, is valued at a fair value by the pricing committee, under the ultimate supervision of the Board of Trustees, following the guidelines and/or procedures adopted by the Board of Trustees.

The Fund also may use fair value pricing, pursuant to guidelines adopted by the Board of Trustees and under the ultimate supervision of the Board of Trustees, if the value of a foreign security it holds is materially affected by events occurring before the Fund’s pricing time but after the close of the primary markets or exchanges on which the security is traded. Those procedures may utilize valuations furnished by pricing services approved by the Board of Trustees, which may be based on market transactions for comparable securities and various relationships between securities that are generally recognized by institutional traders, a computerized matrix system, or appraisals derived from information concerning the securities or similar securities received from recognized dealers in those securities.

When fair value pricing of securities is employed, the prices of securities used by the Fund to calculate its NAV may differ from market quotations or official closing prices. In light of the judgment involved in fair valuations, there can be no assurance that a fair value assigned to a particular security is accurate.


18		Global Total Return Fund ANNUAL REPORT Notes to Financial Statements

Notes to Financial Statements

Investment Transactions. Short-term and long-term investment transactions are recorded on a trade date basis as of October 31, 2007. Net realized gains and losses from investment transactions are reported on an identified cost basis. Interest income is recognized using the accrual method and includes accretion of original issue and market discount and amortization of premium. Dividend income is recognized on the ex-dividend date, except that certain dividends from foreign securities are recorded as soon as the information becomes available.

Foreign Currency Translation. Values of investments and other assets and liabilities denominated in foreign currencies are translated into U.S. dollars using a rate quoted by a major bank or dealer in the particular currency market, as reported by a recognized quotation dissemination service.

The Fund does not isolate that portion of the results of operations resulting from changes in foreign exchange rates on investments from the fluctuations arising from changes in market prices of securities held. Such fluctuations are included with the net realized and unrealized gain or loss from investments.

Recorded net realized foreign currency gains or losses arise from disposition of foreign currency, the difference in the foreign exchange rates between the trade and settlement dates on securities transactions, and the difference between the amounts of dividends, interest and foreign withholding taxes recorded on the ex-date or accrual date and the U.S. dollar equivalent of the amounts actually received or paid. Net unrealized foreign exchange gains and losses arise from changes (due to the changes in the exchange rate) in the value of foreign currency and other assets and liabilities denominated in foreign currencies held at period end.

Option Transactions. For hedging and investment purposes, the Fund may purchase or write (sell) put and call options. One of the risks associated with purchasing an option is that the Fund pays a premium whether or not the option is exercised. Additionally, the Fund bears the risk of loss of premium and change in market value should the counterparty not perform under the contract. Put and call options purchased are accounted for in the same manner as portfolio securities. The cost of securities acquired through the exercise of call options is increased by premiums paid. The proceeds from securities sold through the exercise of put options are decreased by the premiums paid.

When the Fund writes an option, an amount equal to the premium received by the Fund is recorded as a liability and is subsequently adjusted to the current value of the option written. Premiums received from writing options that expire unexercised are treated by the Fund on the expiration date as realized gains from written options. The difference between the premium and the amount paid on effecting a closing purchase transaction, including brokerage commissions, is also treated as a realized gain, or, if the premium is less than the amount paid for the closing purchase transaction, as a realized loss. If a written call option is exercised, the premium is added to the proceeds from the sale of the underlying security or currency in determining whether the Fund has realized a gain or loss. If a written put option is exercised, the premium reduces the cost basis of the securities purchased by the Fund. The Fund as writer of an option bears the market risk of an unfavorable change in the price of the security underlying the written option.

Allocation of Expenses Among Funds. Expenses directly attributable to the Fund are charged to the Fund; certain other expenses of Calamos Investment Trust, Calamos Advisors Trust, Calamos Convertible Opportunities and Income Fund, Calamos Convertible and High Income Fund, Calamos Strategic Total Return Fund, Calamos Global Total Return Fund and Calamos Global Dynamic Income Fund are allocated proportionately among each fund in relation to the net assets of each fund or on another reasonable basis.

Use of Estimates. The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results may differ from those estimates.

Income Taxes. No provision has been made for U.S. income taxes because the Fund’s policy is to continue to qualify as regulated investment company under the Internal Revenue Code of 1986, as amended (the “Code”), and distribute to shareholders substantially all of its taxable income and net realized gains.


Global Total Return Fund Notes to Financial Statements ANNUAL REPORT			19

Notes to Financial Statements

Dividends and distributions paid to shareholders are recorded on the ex-dividend date. The amount of dividends and distributions from net investment income and net realized capital gains is determined in accordance with federal income tax regulations, which may differ from U.S. generally accepted accounting principles. To the extent these “book/tax” differences are permanent in nature, such amounts are reclassified within the capital accounts based on their federal tax-basis treatment. These differences are primarily due to differing treatments for foreign currency transactions, contingent payment debt instruments and methods of amortizing and accreting on fixed income securities. The financial statements are not adjusted for temporary differences.

Indemnifications. Under the Fund’s organizational documents, the Fund is obligated to indemnify its officers and trustees against certain liabilities incurred by them by reason of having been an officer or trustee of the Fund. In addition, in the normal course of business, the Fund may enter into contracts that provide general indemnifications to other parties. The Fund’s maximum exposure under these arrangements is unknown as this would involve future claims that may be made against the Fund that have not yet occurred. Currently, the Fund’s management expects the risk of material loss in connection to a potential claim to be remote.

New Accounting Pronouncements. On July 13, 2006, the Financial Accounting Standards Board (FASB) released FASB Interpretation No. 48 Accounting for Uncertainty in Income Taxes (FIN 48). FIN 48 provides guidance for how uncertain tax positions should be recognized, measured, presented and disclosed in the financial statements. FIN 48 requires the evaluation of tax positions taken in the course of preparing the Fund’s tax returns to determine whether the tax positions are “more-likely-than-not” of being sustained by the applicable tax authority. Tax benefits of positions not deemed to meet the more-likely-than-not threshold would be recorded as a tax expense in the current year. Adoption of FIN 48 is required for fiscal years beginning after December 15, 2006 and is to be applied to all open tax years as of the effective date. At this time, management is evaluating the implications of FIN 48, and its impact on the financial statements has not yet been determined.

In addition, in September 2006, the Statement of Financial Accounting Standards No. 157, Fair Value Measurements (SFAS 157), was issued and is effective for fiscal years beginning after November 15, 2007. SFAS 157 defines fair value, establishes a framework for measuring fair value and expands disclosures about fair value measurements. Management is currently evaluating the impact the adoption of SFAS 157 will have on the Fund’s financial statements, and their disclosures and its impact has not yet been determined.

NOTE 2 — INVESTMENT ADVISOR AND TRANSACTIONS WITH AFFILIATES OR CERTAIN OTHER PARTIES

Pursuant to an investment advisory agreement with Calamos Advisors LLC (“Calamos Advisors”), the Fund pays an annual fee, payable monthly, equal to 1.00% based on the average weekly managed assets. Calamos Advisors has contractually agreed to waive a portion of its advisory fee charged to the Fund on the Fund’s investments in the Calamos Government Money Market Fund (“GMMF,” an affiliated fund and a series of Calamos Investments Trust), equal to the advisory fee attributable to the Fund’s investment in GMMF, based on daily net assets. For the year ended October 31, 2007, the total advisory fee waived pursuant to such agreement was $2,477 and is included in the statement of operations under the caption “Less expense reduction”.

Pursuant to a financial accounting services agreement, the Fund also pays Calamos Advisors a fee for financial accounting services payable monthly at the annual rate of 0.0175% on the first $1 billion of combined assets; 0.0150% on the next $1 billion of combined assets and 0.0110% on combined assets above $2 billion (for purposes of this calculation “combined assets” means the sum of the total average daily net assets of Calamos Investment Trust and Calamos Advisors Trust, and the total average weekly managed assets of Calamos Convertible and High Income Fund, Calamos Convertible Opportunities and Income Fund, Calamos Strategic Total Return Fund, Calamos Global Total Return Fund and Calamos Global Dynamic Income Fund). “Managed assets” means the Fund’s total assets (including any assets attributable to any leverage that may be outstanding) minus total liabilities (other than debt representing financial leverage). Financial accounting services include, but are not limited to, the following: managing expenses and expenses payment processing; monitoring the calculation of expense accrual amounts; calculating, tracking and reporting tax adjustments on all assets; and monitoring trustee deferred compensation plan accruals and valuations. The Fund pays its pro rata share of the financial accounting services fee to Calamos Advisors based on the Fund’s respective managed assets and/or net assets used in calculating the fee.


20		Global Total Return Fund ANNUAL REPORT Notes to Financial Statements

Notes to Financial Statements

The Fund reimburses Calamos Advisors for a portion of compensation paid to the Fund’s Chief Compliance Officer. This compensation is reported as part of “Trustees’ fee and officer compensation” expenses on the Statement of Operations.Included in the statement of operations under the caption “Less expense reduction” are expense offsets of $5,832, arising from credits on cash balances maintained on deposit with the Fund’s custodian.

Certain officers and trustees of the Fund are also officers and directors of Calamos Financial Services LLC (“CFS”) and Calamos Advisors. All such officers and affiliated trustees serve without direct compensation from the Fund, except for the Chief Compliance Officer as described above.

The Fund has adopted a deferred compensation plan (the “Plan). Under the Plan, a trustee who is not an “interested person” (as defined in the 1940 Act) of the Fund and has elected to participate in the Plan (a “participating trustee”) may defer receipt of all or a portion of his compensation from the Fund. The deferred compensation payable to the participating trustee is credited to the trustee’s deferral account as of the business day such compensation would have been paid to the participating trustee. The value of amount deferred for a participating trustee is determined by reference to the change in value of Class I shares of one or more funds of Calamos Investment Trust designated by the participant. The value of the account increases with contributions to the account or with increases in the value of the measuring shares, and the value of the account decreases with withdrawals from the account or with declines in the value of the measuring shares. Deferred compensation investments of $17,669 is included in “Other assets” on the Statement of Assets and Liabilities at October 31, 2007. The Fund’s obligation to make payments under the Plan is a general obligation of the Fund and is included in “Payable for deferred compensation to Trustees” on the Statement of Assets and Liabilities at October 31, 2007.

NOTE 3 — INVESTMENTS

Purchases and sales of investments, other than short-term investments, for the year ended October 31, 2007 were as follows:


Purchases	$	171,519,737
Proceeds from sales	$	179,153,867

The following information is presented on a Federal income tax basis as of October 31, 2007. Differences between the cost basis under U.S. generally accepted accounting principals and federal income tax purposes are primarily due to timing differences.

The cost basis of investments for Federal income tax purposes at October 31, 2007 was as follows:


Gross basis of investments	$	187,685,356

Gross unrealized appreciation		57,484,707
Gross unrealized depreciation		(2,869,247	)

Net unrealized appreciation (depreciation)	$	54,615,460

NOTE 4 — INCOME TAXES

For the year ended October 31, 2007, the Fund recorded the following permanent reclassifications to reflect tax character. Results of operations and net assets were not affected by these reclassifications.


Paid-in capital	$	—
Undistributed net investment income (loss)		3,440,049
Accumulated net realized gain/(loss) on investments, written options and foreign currency transactions		(3,440,049	)

Distributions during the fiscal year ended October 31, 2006 and October 31, 2007 were characterized for Federal income tax purposes as follows:


	2007		2006

Distributions paid from:
Ordinary income	$	11,287,255	$	8,980,754
Long-term capital gains		1,526,024		—


Global Total Return Fund Notes to Financial Statements ANNUAL REPORT			21

Notes to Financial Statements

As of October 31, 2007, the components of accumulated earnings/(loss) on a tax basis were as follows:


Undistributed ordinary income	$	—
Undistributed capital gains		1,129,096

Total undistributed earnings		1,129,096
Accumulated capital and other losses		—
Net unrealized gains/(losses)		53,852,425

Total accumulated earnings/(losses)		54,981,521
Other		(22,679	)
Paid-in capital		113,591,761

Net assets applicable to common shareholders	$	168,550,603

NOTE 5 – COMMON SHARES

There are unlimited common shares of beneficial interest authorized and 8,006,981 shares outstanding at October 31, 2007. Calamos Advisors owned 7,915 of the outstanding shares at October 31, 2007. Transactions in common shares were as follows:


	For the Year Ended		For the Year Ended
	October 31, 2007		October 31, 2006

Beginning shares		8,006,981		8,006,981
Shares issued through reinvestment of distributions		—		—

Ending shares		8,006,981		8,006,981

NOTE 6 – FORWARD FOREIGN CURRENCY CONTRACTS

The Fund may engage in portfolio hedging with respect to changes in currency exchange rates by entering into foreign currency contracts to purchase or sell currencies. A forward foreign currency contract is a commitment to purchase or sell a foreign currency at a future date at a negotiated forward rate. Risks associated with such contracts include, among other things, movement in the value of the foreign currency relative to U.S. dollar and the ability of the counterparty to perform. The net unrealized gain, if any, represents the credit risk to the Fund on a forward foreign currency contract. The contracts are valued daily at forward foreign exchange rates and an unrealized gain or loss is recorded. The Fund realizes a gain or loss when a position is closed or upon settlement of the contracts. There were no open forward currency contracts at October 31, 2007.

NOTE 7 — PREFERRED SHARES

There are unlimited shares of Auction Rate Cumulative Preferred Shares (“Preferred Shares”) authorized. The Preferred Shares have rights as determined by the Board of Trustees. The 2,360 shares of Preferred Shares outstanding consist of one series, 2,360 shares of T. The Preferred Shares have a liquidation value of $25,000 per share plus any accumulated but unpaid dividends, whether or not declared.

Dividends on the Preferred Shares are cumulative at a rate typically reset every seven or twenty-eight days based on the results of an auction. Dividend rates ranged from 4.90% to 6.25% for the year ended October 31, 2007. Under the 1940 Act, the Fund may not declare dividends or make other distributions on its common shares or purchase any such shares if, at the time of the declaration, distribution or purchase, asset coverage with respect to the outstanding Preferred Shares would be less than 200%.

The Preferred Shares are redeemable at the Fund’s option, in whole or in part, on any dividend payment date at $25,000 per share plus any accumulated but unpaid dividends. The Preferred Shares are also subject to mandatory redemption at $25,000 per share plus any accumulated but unpaid dividends, whether or not declared, if certain requirements relating to the composition of the assets and liabilities of the Fund as set forth in the Statement of Preferences are not satisfied.

Global Total Return Fund
22 ANNUAL REPORT Notes to Financial Statements

Notes to Financial Statements

The holders of Preferred Shares have voting rights equal to the holders of common shares (one vote per share) and will vote together with holders of common shares as a single class except on matters affecting only the holders of Preferred Shares or only the holders of common shares, when the respective classes vote alone.

NOTE 8 – WRITTEN OPTIONS TRANSACTIONS

The Fund may engage in option transactions and in doing so achieve the similar objectives to what it would achieve through the sale or purchase of individual securities. For the fiscal year ended October, 31, 2007, the Fund had the following transactions in options written:


	Number of			Premiums
	Contracts			Received

Options outstanding at October 31, 2006		7,550		$	1,441,680
Options written		24,300			5,960,197
Options closed		(22,598	)		(4,669,986	)
Options expired		—			—
Options exercised		(2,252	)		(387,047	)

Options outstanding at October 31, 2007		7,000		$	2,344,844

NOTE 9 – SECURITIES LENDING

For the fiscal year ended October 31, 2007, the Fund loaned one or more of its securities to broker-dealers and banks. Any such loan must be continuously secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the market value of the securities loaned by the Fund. The Fund continues to receive the equivalent of the interest or dividends paid by the issuer on the securities loaned and also receives an additional return that may be in the form of a fixed fee or a percentage of the collateral. The Fund may pay reasonable fees to persons unaffiliated with the Fund for services in arranging these loans. The Fund has the right to call the loan and obtain the securities loaned at any time on notice of not less than five business days. The Fund does not have the right to vote the securities during the existence of the loan but could call the loan in an attempt to permit voting of the securities in certain circumstances. Upon return of the securities loaned, the cash or cash equivalent collateral will be returned to the borrower. In the event of bankruptcy or other default of the borrower, the Fund could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses, including (a) possible decline in the value of the collateral or in the value of the securities loaned during the period while the Fund seeks to enforce its rights thereto, (b) possible subnormal levels of income and lack of access to income during this period, and (c) the expenses of enforcing its rights. The market value of the loaned securities is determined at the close of business of the Fund and any additional required collateral is delivered to the Fund the next day. In an effort to reduce these risks, the Fund’s security lending agent monitors and reports to Calamos Advisors on the creditworthiness of the firms to which the Fund lends securities. At October 31, 2007, the Fund had securities valued at $13,457,659 on loan to broker-dealers and banks and $13,371,000 in cash or cash equivalent collateral.

NOTE 10 – SYNTHETIC CONVERTIBLE SECURITIES

The Fund may establish a “synthetic’’ convertible instrument by combining separate securities that possess the economic characteristics similar to a convertible security, i.e., fixed-income securities (“fixed-income component’’, which may be a convertible or non-convertible security) and the right to acquire equity securities (“convertible component’’). The fixed-income component is achieved by investing in fixed income securities such as bonds, preferred stocks and money market instruments. The convertible component is achieved by investing in warrants or options to buy common stock at a certain exercise price, or options on a stock index. In establishing a synthetic instrument, the Fund may pool a basket of fixed-income securities and a basket of warrants or options that produce the economic characteristics similar to a convertible security. Within each basket of fixed-income securities and warrants or options, different companies may issue the fixed-income and convertible components, which may be purchased separately and at different times.

Global Total Return Fund
Notes to Financial Statements ANNUAL REPORT 23

Notes to Financial Statements

The Fund may also purchase synthetic securities created by other parties, typically investment banks, including convertible structured notes. Convertible structured notes are fixed-income debentures linked to equity. Convertible structured notes have the attributes of a convertible security; however, the investment bank that issued the convertible note assumes the credit risk associated with the investment, rather than the issuer of the underlying common stock into which the note is convertible. Purchasing synthetic convertible securities may offer more flexibility than purchasing a convertible security.

Global Total Return Fund
24 ANNUAL REPORT Notes to Financial Statements

Financial Highlights

Selected data for a common share outstanding throughout each period were as follows:


							October 27,
							2005*
	For the						through
	Year Ended October 31,						October 31,
	2007			2006			2005

Net asset value, beginning of period	$	16.31		$	14.29		$	14.32	(a)

Income from investment operations:
Net investment income (loss)		0.96	**		0.86			—	(b)

Net realized and unrealized gain (loss) from investments, written options and foreign currency		5.38			2.40			—

Distributions to preferred shareholders from:
Net investment income (common share equivalent basis)		(0.39	)		(0.29	)		—

Capital gains (common share equivalent basis)		—	b		—			—

Total from investment operations		5.95			2.97			—

Less distributions to common shareholders from:
Net investment income		(1.09	)		(0.65	)		—

Capital gains		(0.12	)		(0.19	)		—

Capital charge resulting from issuance of common and preferred shares		—			(0.11	)		(0.03	)

Net asset value, end of period	$	21.05		$	16.31		$	14.29

Market value, end of period	$	19.51		$	15.62		$	15.00

Total investment return based on(c):
Net asset value		38.30	%		20.77	%		(0.24	)%
Market value		33.84	%		10.19	%		0.00	%

Ratios and supplemental data:
Net assets applicable to common shareholders, end of period (000’s omitted)	$	168,551		$	130,588		$	114,439

Preferred shares, at redemption value ($25,000 per share liquidation preference) (000’s omitted)	$	59,000		$	59,000		$	—

Ratios to average net assets applicable to common shareholders:
Net expenses(d)(e)		1.72	%		1.70	%		1.33	%

Gross expenses(d)(e)		1.72	%		1.70	%		3.37	%

Net investment income (loss)(d)(e)		5.37	%		5.57	%		(1.33	)%

Preferred share distributions from net investment income		2.17	%		1.89	%		0.00	%

Net investment income (loss), net of preferred share distributions from net investment income		3.20	%		3.68	%		0.00	%

Portfolio turnover rate		85	%		32	%		0	%

Average commission rate paid	$	0.0377		$	0.0258		$	—

Asset coverage per preferred share, at end of period(f)	$	96,423		$	80,358		$	—


*		Commencement of operations.

**		Net investment income allocated based on average shares method.

(a)		Net of sales load of $0.675 on initial shares issued and beginning net asset value of $14.325.

(b)		Amount equated to less than $0.005 per common share.

(c)		Total investment return is calculated assuming a purchase of common shares on the opening of the first day and a sale on the closing of the last day of the period reported. Dividends and distributions are assumed, for purposes of this calculation, to be reinvested at prices obtained under the Fund’s dividend reinvestment plan. Total return is not annualized for periods less than one year. Brokerage commissions are not reflected. NAV per share is determined by dividing the value of the Fund’s portfolio securities, cash and other assets, less all liabilities, by the total number of common shares outstanding. The common share market price is the price the market is willing to pay for shares of the Fund at a given time. Common share market price is influenced by a range of factors, including supply and demand and market conditions.

(d)		Annualized for periods less than one year.

(e)		Does not reflect the effect of dividend payments to the shareholders of Preferred Shares.

(f)		Calculated by subtracting the Fund’s total liabilities (not including Preferred Shares) from the Fund’s total assets and dividing this by the number of Preferred Shares outstanding.


Global Total Return Fund
Financial Highlights ANNUAL REPORT			25

Report of Independent Registered Public Accounting Firm

To the Board of Trustees and Shareholders of Calamos Global Total Return Fund

We have audited the accompanying statement of assets and liabilities, including the schedule of investments, of CALAMOS Global Total Return Fund (the “Fund”) as of October 31, 2007, and the related statement of operations for the year then ended, the statements of changes in net assets for each of the two years then ended, and the financial highlights for each of the two years then ended and for the period from October 27, 2005 (commencement of operations) through October 31, 2005. These financial statements and financial highlights are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements and financial highlights based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement. The Fund is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. Our audits included consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the Fund’s internal control over financial reporting. Accordingly, we express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. Our procedures included confirmation of securities owned as of October 31, 2007, by correspondence with the Fund’s custodian and brokers. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements and financial highlights referred to above present fairly, in all material respects, the financial position of the Fund as of October 31, 2007, the results of its operations for the year then ended, the changes in its net assets for each of the two years then ended, and the financial highlights for each of the two years then ended and for the period from October 27, 2005 (commencement of operations) through October 31, 2005, in conformity with accounting principles generally accepted in the United States of America.

Chicago, Illinois
December 14, 2007


		Global Total Return Fund
26		ANNUAL REPORT Report of Independent Registered Public Accounting Firm

Trustee Approval of Management Agreement (unaudited)

The Board of Trustees of the Fund oversees the Fund’s management, and, as required by law, determines annually whether to continue the Fund’s management agreement with Calamos Advisors under which Calamos Advisors serves as the investment manager and administrator for the Fund. The “Independent Trustees,” who comprise more than 80% of the Board, have never been affiliated with Calamos Advisors.

In connection with their most recent consideration regarding the continuation of the management agreement, the Trustees received and reviewed a substantial amount of information provided by Calamos Advisors in response to detailed requests of the Independent Trustees and their independent legal counsel. In the course of their consideration of the agreement, the Independent Trustees were advised by their counsel and, in addition to meeting with management of Calamos Advisors, they met separately in executive session with their counsel.

At a meeting on June 22, 2007, based on their evaluation of the information referred to above and other information, the Trustees determined that the overall arrangements between the Fund and Calamos Advisors were fair and reasonable in light of the nature, extent and quality of the services provided by Calamos Advisors and its affiliates, the fees charged for those services and other matters that the Trustees considered relevant in the exercise of their business judgment. At that meeting, the Trustees, including all of the Independent Trustees, approved continuation of the management agreement through July 31, 2008, subject to possible earlier termination as provided in the agreement.

In considering the continuation of the management agreement, the Trustees reviewed various factors that they determined were relevant, including the factors described below, none of which by itself was considered the sole factor in the Trustees’ determinations. However, the material factors and conclusions that formed the basis for the Trustees’ determinations to approve the continuation of the management agreement are discussed separately below.

Nature, Extent and Quality of Services

The Trustees reviewed the nature, extent and quality of Calamos Advisors’ services to the Fund, taking into account the Fund’s investment objective and strategy and their knowledge gained from their regular meetings with management on at least a quarterly basis and their ongoing review of information related to the Fund. In addition, the Trustees reviewed Calamos Advisors’ resources and key personnel, especially those who provide investment management services to the Fund. The Trustees also considered other services provided to the Fund by Calamos Advisors, such as managing the execution of portfolio transactions and the selection of broker-dealers for those transactions, serving as the Fund’s administrator, monitoring adherence to the Fund’s investment restrictions, producing shareholder reports, providing support services for the Board and Board committees, communicating with shareholders, overseeing the activities of other service providers, and monitoring compliance with various Fund policies and procedures and with applicable securities laws and regulations. In addition, the Trustees considered compliance reports from the Fund’s Chief Compliance Officer.

The Trustees concluded that the nature, quality and extent of the services provided or to be provided to the Fund by Calamos Advisors were appropriate and consistent with the terms of the management agreement and that the Fund was likely to benefit from the continued provision of those services.

Performance of the Fund

The Trustees considered the Fund’s performance results over various time periods. They reviewed information comparing the performance of the Fund with the performance of a universe of comparable funds identified by Lipper Inc., an independent provider of investment company data, and with the Fund’s benchmark. The Trustees discussed Fund performance with representatives of Calamos Advisors, who provided additional information with regard to certain aspects of the Lipper


Global Total Return Fund
Trustee Approval of Management Agreement ANNUAL REPORT			27

Trustee Approval of Management Agreement (unaudited)

materials. The Trustees noted that the Fund had less than three years of performance data, and thus did not have a long-term performance record. The Trustees concluded that the Fund’s operating history was too short a period to allow for a meaningful performance comparison.

Costs of Services and Profits Realized by Calamos Advisors

The Trustees examined information regarding the Fund’s fees and expenses in comparison to corresponding information for comparable funds as provided by Lipper. Also, the Trustees reviewed information on fees and expenses for additional funds identified by Calamos Advisors. The Trustees noted that, although the Fund’s contractual rate of management fees, actual management fees and overall expense ratio were higher than the peer group medians, each of those data points appeared reasonable in light of the other factors considered by the Trustees.

The Trustees also reviewed the rates of management fees charged by Calamos Advisors to its separate accounts and to its subadvised funds (for which Calamos Advisors provides portfolio management services only). Although in most instances its sub-advisory fees, and in many instances its separate account fees, for various comparable investment strategies are lower than the management fees charged to the Fund, the Trustees noted that Calamos Advisors performs significant additional services for the Fund that it does not provide to those other clients. Those services include administrative services, oversight of the Fund’s other service providers, trustee support, regulatory compliance and numerous other services. The Trustees also considered that, in serving the Fund, Calamos Advisors assumes many risks that it does not assume in servicing its other clients.

The Trustees considered the methodology used by Calamos Advisors in determining compensation payable to portfolio managers, the competitive environment for investment management talent, and the competitive market for mutual funds in different distribution channels.

The Trustees reviewed information on the profitability of Calamos Advisors in serving as the Fund’s investment manager and of Calamos Advisors and its affiliates in all of their relationships with the Fund, as well as an explanation of the methodology utilized in allocating various expenses among the Fund and other business units. Data was provided to the Trustees with respect to profitability, both on a pre- and post-marketing cost basis. The Trustees also reviewed the annual report of Calamos Advisors’ parent company and discussed its corporate structure. The Trustees recognized that profitability comparisons among fund managers are difficult because very little comparative information is publicly available and profitability of any manager is affected by numerous factors, including the particular manager’s organizational structure, the types of funds and other accounts it manages, possible other lines of business, the methodology for allocating expenses and the manager’s capital structure and cost of capital. However, based on the information available and taking those factors into account, the Trustees concluded that the profitability of Calamos Advisors with respect to the Fund in relation to the services rendered was not unreasonable.

The Trustees concluded that the management fees payable by the Fund to Calamos Advisors were reasonable in relation to the nature and quality of the services to be provided, taking into account the fees charged by other advisers for managing comparable funds with similar strategies and the fees Calamos Advisors charges to other clients. The Trustees also concluded that the Fund’s overall expense ratio was reasonable in light of the quality and extent of services provided by Calamos Advisors, the size of the Fund and the Fund’s investment performance.

Economies of Scale

In reviewing the Fund’s fees and expenses, the Trustees examined the potential benefits of economies of scale and whether any economies of scale should be reflected in the Fund’s fee structure. They noted that the Fund has had a relatively stable asset base since commencement of operation and that there do not appear to have been any significant economies of scale realized since that time.


		Global Total Return Fund
28		ANNUAL REPORT Trustee Approval of Management Agreement

Trustee Approval of Management Agreement (unaudited)

Other Benefits to Calamos Advisors

The Trustees also considered benefits that accrue to Calamos Advisors and its affiliates from their relationship with the Fund. The Trustees concluded that, other than the services to be provided by Calamos Advisors and its affiliates pursuant to their agreements with the Fund and the fees payable by the Fund therefor, the Fund and Calamos Advisors may potentially benefit from their relationship with each other in other ways. The Trustees also considered Calamos Advisors’ use of commissions paid by the Fund on its portfolio brokerage transactions to obtain proprietary research products and services benefiting the Fund and/or other clients of Calamos Advisors. The Trustees concluded, based on reports from the Fund’s Chief Compliance Officer, that Calamos Advisors’ use of “soft” commission dollars to obtain research products and services was consistent with regulatory requirements.

After full consideration of the above factors as well as other factors that were instructive in considering the management arrangements, the Trustees, including all of the Independent Trustees, concluded that the continuation of the management agreement with Calamos Advisors was in the best interest of the Fund and its shareholders.


Global Total Return Fund Trustee Approval of Management Agreement ANNUAL REPORT			29

Tax Information (unaudited)

We are providing this information as required by the Internal Revenue Code (Code). The amounts shown may differ from those elsewhere in this report due to differences between tax and financial reporting requirements. In January 2008, shareholders will receive Form 1099-DIV which will include their share of qualified dividends and capital gains distributed during the calendar year 2007. Shareholders are advised to check with their tax advisors for information on the treatment of these amounts on their individual income tax returns.

Under Section 852(b)(3)(c) of the code, the Fund hereby designates $1,526,024 as capital gain dividends for the fiscal year ended October 31, 2007.

Under Section 854(b)(2) of the Code, the Fund hereby designates $3,195,794 or the maximum amount allowable under the Code, as qualified dividends for the fiscal year ended October 31, 2007.

Under Section 854(b)(2) of the Code, the Fund hereby designates 21.93% of the ordinary income dividends as income qualifying for the corporate dividends received deduction for the fiscal year ended October 31, 2007.


30		Global Total Return Fund ANNUAL REPORT Tax Information

Trustees & Officers (unaudited)

The management of the Trust+, including general supervision of the duties performed for the Fund under the investment management agreement between the Trust and Calamos Advisors, is the responsibility of its board of trustees. Each trustee elected will hold office for the lifetime of the Trust or until such trustee’s earlier resignation, death or removal; however, each trustee who is not an interested person of the Trust shall retire as a trustee at the end of the calendar year in which the trustee attains the age of 72 years.

The following table sets forth each trustee’s name, age at October 31, 2007, position(s) with the Trust, number of portfolios in the Calamos Fund Complex overseen, principal occupation(s) during the past five years and other directorships held, and date first elected or appointed. Each trustee oversees each Fund of the Trust.


		Portfolios in
		Fund Complex^		Principal Occupation(s)
Name and Age	Position(s) Held with Trust	Overseen		and Other Directorships Held


Trustees who are interested persons of Trust:
John P. Calamos, Sr., 67*	Trustee and President (since 2004)		19	Chairman, CEO, and Co-Chief Investment Officer Calamos Asset Management, Inc. (“CAM”), Calamos Holdings LLC (“CHLLC”) and Calamos Advisors LLC and its predecessor (“Calamos Advisors”), and President and Co-Chief Investment Officer, Calamos Financial Services LLC and its predecessor (“CFS”); Director, CAM

Trustees who are not interested persons of Trust:
Joe F. Hanauer, 70	Trustee (since 2004)		19	Private investor; Director, MAF Bancorp (bank holding company); Chairman and Director, Move, Inc., (internet provider of real estate information and products); Director, Combined Investments, L.P. (investment management)
Weston W. Marsh, 57	Trustee (since 2004)		19	Of Counsel and prior thereto, Partner, Freeborn & Peters (law firm)
John E. Neal, 57	Trustee (since 2004)		19	Private investor; Managing Director, Banc One Capital Markets, Inc. (investment banking) (2000-2004); Director, Focused Health Services (private disease management company), Equity Residential (publicly- owned REIT), Ranir LLC (oral products company) and CBA Commercial (commercial mortgage securitization company); Partner, Private Perfumery LLC (private label perfume company) and Linden LLC (health care private equity)
William R. Rybak, 56	Trustee (since 2004)		19	Private investor; formerly Executive Vice President and Chief Financial Officer, Van Kampen Investments, Inc. and subsidiaries (investment manager); Director, Howe Barnes Hoefer Arnett, Inc. (investment services firm) and PrivateBancorp, Inc. (bank holding company); Trustee, JNL Series Trust, JNL Investors Series Trust and JNL Variable Fund LLC**
Stephen B. Timbers, 63	Trustee (since 2004); Lead Independent Trustee (since 2005)		19	Private investor; formerly Vice Chairman, Northern Trust Corporation (bank holding company); formerly President and Chief Executive Officer, Northern Trust Investments, N.A. (investment manager); formerly President, Northern Trust Global Investments, a division of Northern Trust Corporation and Executive Vice President, The Northern Trust Corporation; Director, Northern Trust Securities, Inc.
David D. Tripple, 63	Trustee (since 2006)		19	Private investor; Trustee, Century Shares Trust and Century Small Cap Select Fund***


+		The trust is defined as the Calamos Global Total Return Fund.

*		Mr. Calamos is an “interested person” of the Trust as defined in the 1940 Act because he is an officer of the Trust and an affiliate of Calamos Advisors and Calamos Financial Services LLC.

**		Overseeing 94 portfolios in fund complex

***		Overseeing 2 portfolios in fund complex

^		The Fund Complex consists of CALAMOS Investment Trust, CALAMOS Advisors Trust, CALAMOS Convertible Opportunities and Income Fund, CALAMOS Convertible and High Income Fund, CALAMOS Strategic Total Return Fund, CALAMOS Global Total Return Fund and CALAMOS Global Dynamic Income Fund.

The address of each trustee is 2020 Calamos Court, Naperville, IL 60563.


Global Total Return Fund			31
Trustees & Officers ANNUAL REPORT

Trustees & Officers (unaudited)

Officers. The preceding table gives information about John P. Calamos, Sr., who is president of the Trust. The following table sets forth each other officer’s name, age at October 31, 2007, position with the Trust and date first appointed to that position, and principal occupation(s) during the past five years. Each officer serves until his or her successor is chosen and qualified or until his or her resignation or removal by the board of trustees.


		Principal Occupation(s)
Name and Age	Position(s) Held with Trust	During Past 5 Years


Nimish S. Bhatt, 44	Treasurer (since 2004)	Senior Vice President and Director of Operations, CAM, CHLLC, Calamos Advisors and CFS (since 2004); Senior Vice President, Alternative Investments and Tax Services, The BISYS Group, Inc., prior thereto

Nick P. Calamos, 46	Vice President (since 2004)	Senior Executive Vice President and Co-Chief Investment Officer, CAM, CHLLC, Calamos Advisors and CFS

Patrick H. Dudasik, 52	Vice President (since 2004)	Executive Vice President, Chief Financial Officer and Treasurer, CAM and CHLLC (since 2004), Calamos Advisors and CFS (since 2001); Chief Operating Officer, CAM, CHLLC, Calamos Advisors and CFS (since 2007) Administrative Officer, CAM and CHLLC (2004-2005), Calamos Advisors and CFS (2001-2005)

Mark Mickey, 56	Chief Compliance Officer (since 2005)	Chief Compliance Officer, Calamos Funds (since 2005) and Chief Compliance Officer, Calamos Advisors (2005-2006); Director of Risk Assessment and Internal Audit, Calamos Advisors (2003-2005); President, Mark Mickey Consulting (2002-2003)

The address of each officer is 2020 Calamos Court, Naperville, IL 60563.

Proxy Voting Policies. A description of the CALAMOS Proxy Voting Policies and Procedures is available by calling 800-582-6959, by visiting its website at www.calamos.com or by writing CALAMOS at: CALAMOS INVESTMENTS, Attn: Client Services, 2020 Calamos Court, Naperville, IL 60563, and on the SEC’s website at www.sec.gov.


32		Global Total Return Fund ANNUAL REPORT Trustees & Officers

About Closed-End Funds

What is a Closed-End Fund?

A closed-end fund is a publicly traded investment company that raises its initial investment capital through the issuance of a fixed number of shares to investors in a public offering. Shares of a closed-end fund are listed on a stock exchange or traded in the over-the-counter market. Like all investment companies, a closed-end fund is professionally managed and offers investors a unique investment solution based on its investment objective approved by the fund’s Board of Directors.

Potential Advantages of Closed-End Fund Investing

•

Defined Asset Pool Allows Efficient Portfolio Management—Although closed-end fund shares trade actively on a securities exchange, this doesn’t affect the closed-end fund manager because there are no new investors buying into or selling out of the fund’s portfolio.

•

More Flexibility in the Timing and Price of Trades—Investors can purchase and sell shares of closed-end funds throughout the trading day, just like the shares of other publicly traded securities.

•

Lower Expense Ratios—The expense ratios of closed-end funds are oftentimes less than those of mutual funds. Over time, a lower expense ratio could enhance investment performance.

•

Closed-End Structure Makes Sense for Less-Liquid Asset Classes—A closed-end structure makes sense for investors considering less-liquid asset classes, such as high-yield bonds or micro-cap stocks.

•

Ability to Put Leverage to Work—Closed-end funds may issue senior securities (such as preferred shares or debentures) or borrow money to “leverage” their investment positions.

•

No Minimum Investment Requirements

OPEN-END MUTUAL FUNDS VERSUS CLOSED-END FUNDS


Open-End Fund		Closed-End Fund
Issues new shares on an ongoing basis		Issues a fixed number of shares
Issues equity shares		Can issue senior securities such as preferred shares and bonds
Sold at NAV plus any sales charge		Price determined by the marketplace
Sold through the fund’s distributor		Traded in the secondary market
Fund redeems shares at NAV calculated at the close of business day		Fund does not redeem shares

Global Total Return Fund
About Closed-End Funds ANNUAL REPORT 33

Leverage

Using Leverage to Enhance Total Return

Closed-end funds can use leverage which utilizes borrowed money in an attempt to increase the return on invested capital. The Fund invests the borrowed assets into securities, which we believe will provide a greater total return to investors than the cost of the borrowing.

Highlights on Leverage

•

Leveraging the portfolio allows the investment team to potentially enhance the income and total returns of the Fund.

•		In leveraged closed-end funds that invest in interest-rate sensitive securities (high-quality traditional fixed income), rising rates can negatively impact a fund in two ways: increasing the cost of leverage and decreasing the value of securities.

•		This portfolio does not have notable sensitivity to rising interest rates. The portfolio seeks to invest in securities that should be more economically sensitive and less interest rate-sensitive.

Global Total Return Fund
34 ANNUAL REPORT Leverage

Level Rate Distribution Policy

Using a Level Rate Distribution Policy to Promote Dependable Income and Total Return The goal of the level rate distribution policy is to provide investors a predictable, though not assured, level of cash flow, which can either serve as a stable income stream or, through reinvestment, contribute significantly to long-term total return.

We understand the importance that investors place on the stability of dividends and their ability to contribute to long-term total return, which is why we have instituted a level rate distribution policy for the Fund. Under the policy, monthly distributions paid may include net investment income, net realized short-term capital gains and, if necessary, return of capital. In addition, a limited number of distributions per calendar year may include net realized long-term capital gains. There is no guarantee that the Fund will realize capital gains in any given year. Distributions are subject to re-characterization for tax purposes after the end of the fiscal year. All shareholders with taxable accounts will receive written notification regarding the components and tax treatment for distributions via Form 1099-DIV.

Distributions from the Fund are generally subject to Federal income taxes. For purposes of maintaining the level rate distribution policy, the Fund may realize short-term capital gains on securities that, if sold at a later date, would have resulted in long-term capital gains. Maintenance of a level rate distribution policy may increase transaction and tax costs associated with the Fund.

Automatic Dividend Reinvestment Plan

Maximizing Investment with an Automatic Dividend Reinvestment Plan

The Automatic Dividend Reinvestment Plan offers a simple, cost-efficient and convenient way to reinvest your dividends and capital gains distributions in additional shares of the Fund, allowing you to increase your investment in the Fund.

Potential Benefits

•

Compounded Growth: By automatically reinvesting with the Plan, you gain the potential to allow your dividends and capital gains to compound over time.

•

Potential for Lower Commission Costs: Additional shares are purchased in large blocks, with brokerage commissions shared among all plan participants. There is no cost to enroll in the Plan.

•

Convenience: After enrollment, the Plan is automatic and includes detailed statements for participants. Participants can terminate their enrollment at any time.

For additional information about the Plan, please contact the Plan Agent, The Bank of New York, at 800.432.8224 or visit us on the web at www.calamos.com/cgo.aspx. If you wish to participate in the Plan and your shares are held in your own name, simply call the Plan Agent. If your shares are not held in your name, please contact your brokerage firm, bank, or other nominee to request that they participate in the Plan on your behalf. If your brokerage firm, bank, or other nominee is unable to participate on your behalf, you may request that your shares be re-registered in your own name.

We’re pleased toprovide our shareholders with the additional benefit of the Fund’s Dividend Reinvestment Plan and hope that it may serve your financial plan.

Global Total Return Fund
Level Rate Distribution Policy and Automatic Dividend Reinvestment Plan ANNUAL REPORT 35

The Calamos Investments Advantage

Calamos’ history is one of performing well for our clients through nearly 30 years of advances and declines in the market. We use proprietary risk-management strategies designed to control volatility, and maintain a balance between risk and reward throughout a market cycle.

Disciplined Investment Philosophy and Process

Calamos Investments has developed a proprietary research and monitoring process that goes far beyond traditional security analysis. This process applies to each of our investment strategies, with emphasis varying by strategy. When combined with the company-specific research and industry insights of our investment team, the goal is nimble, dynamic management of a portfolio that allows us to anticipate and adapt to changing market conditions. In each of our investment strategies, from the most conservative to the most aggressive, our goals include maximizing return while controlling risk, protecting principal during volatile markets, avoiding short-term market timing, and maintaining a vigilant long-term outlook.

Comprehensive Risk Management

Our approach to risk management includes continual monitoring, adherence to our discipline, and a focus on assuring a consistent risk profile during all phases of the market cycle. Incorporating qualitative and quantitative factors as well as a strong sell discipline, this risk-control policy seeks to help preserve investors’ capital over the long term.

Proven Investment Management Team

The Calamos Family of Funds benefits from our team’s decades of experience in the investment industry. We follow a one-team, one-process approach that leverages the expertise of more than 50 investment professionals, led by Co-Chief Investment Officers John P. Calamos, Sr. and Nick P. Calamos, whose investment industry experience dates back to 1970 and 1983, respectively. Through the collective industry experience and educational achievements of our research and portfolio staff, we can respond to the challenges of the market with innovative and timely ideas.

Sound Proprietary Research

Over the years, we have invested significant time and resources in developing and refining sophisticated analytical models that are the foundation of the firm’s research capabilities, which we apply in conjunction with our assessment of broad themes. We believe evolving domestic policies, the growing global economy, and new technologies present long-term investment opportunities for those who can detect them.


36		Global Total Return Fund ANNUAL REPORT The Calamos Investments Advantage

Calamos Closed-End Funds

Intelligent Asset Allocation in Five Distinct Closed-End Funds

Depending on which Calamos closed-end fund you currently own, you may want to consider one or more of our other closed-end strategies to further diversify your investment portfolio.

Seek the advice of your financial advisor, who can help you determine your financial goals, risk tolerance, time horizon and income needs. To learn more, you can also visit our website at www.calamos.com.

Fund Asset Allocation as of 10/31/07

Fund Profile

Calamos Convertible Opportunities and Income Fund (CHI)

Providing Enhanced Fixed Income Potential

Objective: The Fund seeks total return through a combination of capital appreciation and current income by investing in a diversified portfolio of convertible securities and below investment-grade (high-yield) fixed-income securities.

Calamos Convertible and High Income Fund (CHY)

Providing Enhanced Fixed Income Potential

Calamos Global Dynamic Income Fund (CHW)

Providing Global Enhanced Fixed Income Potential

Objective: The Fund seeks to generate a high level of current income with a secondary objective of capital appreciation. The Fund has maximum flexibility to dynamically allocate among equities, fixed-income securities and alternative investments around the world.

Calamos Strategic Total Return Fund (CSQ)

Providing Defensive Equity

Objective: The Fund seeks total return through a combination of capital appreciation and current income by investing in a diversified portfolio of equity, convertible and below investment-grade (high-yield) fixed-income securities.

Calamos Global Total Return Fund (CGO)

Providing Defensive Global Equity

Objective: The Fund seeks total return through a combination of capital appreciation and current income by investing in a diversified portfolio of global equity, global convertible and below investment-grade (high-yield) fixed-income securities.

Fund asset allocations are based on total investments (excluding security lending collateral) and may vary over time.


Global Total Return Fund Calamos Closed-End Funds ANNUAL REPORT		37

ITEM 2. CODE OF ETHICS.

(a) As of the end of the period covered by this report, the registrant has adopted a code of ethics (the “Code of Ethics”) that applies to its principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions.

(b) No response required.

(c) The registrant has not amended its Code of Ethics as it relates to any element of the code of ethics definition enumerated in paragraph(b) of this Item 2 during the period covered by this report.

(d) The registrant has not granted a waiver or an implicit waiver from its Code of Ethics during the period covered by this report.

(e) Not applicable.

(f) (1) The registrant’s Code of Ethics is attached as an Exhibit hereto.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

The registrant’s Board of Trustees has determined that, for the period covered by the shareholder report presented in Item 1 hereto, it has four audit committee financial experts serving on its audit committee, each of whom is an independent Trustee for purpose of this N-CSR Item: John E. Neal, William R. Rybak, Stephen B. Timbers and David D. Tripple. Under applicable securities laws, a person who is determined to be an audit committee financial expert will not be deemed an “expert” for any purpose, including without limitation for the purposes of Section 11 of the Securities Act of 1933, as a result of being designated or identified as an audit committee financial expert pursuant to this Item. The designation or identification of a person as an audit committee financial expert does not impose on such person any duties, obligations, or liabilities that are greater than the duties, obligations and liabilities imposed on such person as a member of the audit committee and board of directors in the absence of such designation or identification. The designation or identification of a person as an audit committee financial expert pursuant to this Item does not affect the duties, obligations, or liabilities of any other member of the audit committee or board of directors.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

a) Audit Fee — $33,192 and $11,222 are the aggregate fees billed in each of the last two fiscal years for professional services rendered by the principal accountant to the registrant for the audit of the registrant’s annual financial statements or services that are normally provided by the accountant in connection with statutory and regulatory filings or engagements for those fiscal years.

(b) Audit-Related Fees — $22,365 and $10,376 are the aggregate fees billed in each of the last two fiscal years for assurance and related services rendered by the principal accountant to the registrant that are reasonably related to the performance of the audit of the registrant’s financial statements and are not reported under paragraph (a) of this Item 4.

(c) Tax Fees — $1,649 and $1,829 are the aggregate fees billed in each of the last two fiscal years for professional services rendered by the principal accountant to the registrant for tax compliance, tax advice, and tax planning.

(d) All Other Fees — $0 and $0 are the aggregate fees billed in each of the last two fiscal years for products and services provided by the principal accountant to the registrant, other than the services reported in paragraph (a)-(c) of this Item 4.

(e)(1) Registrant’s audit committee meets with the principal accountants and management to review and pre-approve all audit services to be provided by the principal accountants.

The audit committee shall pre-approve all non-audit services to be provided by the principal accountants to the registrant, including the fees and other compensation to be paid to the principal accountants;

provided that the pre-approval of non-audit services is waived if (i) the services were not recognized by management at the time of the engagement as non-audit services, (ii) the aggregate fees for all non-audit services provided to the registrant are less than 5% of the total fees paid by the registrant to its principal accountants during the fiscal year in which the non-audit services are provided, and (iii) such services are promptly brought to the attention of the audit committee by management and the audit committee approves them prior to the completion of the audit.

The audit committee shall pre-approve all non-audit services to be provided by the principal accountants to the investment adviser or any entity controlling, controlled by or under common control with the adviser that provides ongoing services to the registrant if the engagement relates directly to the operations or financial reporting of the registrant, including the fees and other compensation to be paid to the principal accountants; provided that pre-approval of non-audit services to the adviser or an affiliate of the adviser is not required if (i) the services were not recognized by management at the time of the engagement as non-audit services, (ii) the aggregate fees for all non-audit services provided to the adviser and all entities controlling, controlled by or under common control with the adviser are less than 5% of the total fees for non-audit services requiring pre-approval under paragraph (e)(1) of this Item 4 paid by the registrant, the adviser or its affiliates to the registrant’s principal accountants during the fiscal year in which the non-audit services are provided, and (iii) such services are promptly brought to the attention of the audit committee by management and the audit committee approves them prior to the completion of the audit.

(e)(2) No percentage of the principal accountant’s fees or services described in each of paragraphs (b)-(d) of this Item were approved pursuant to the waiver provision of paragraph (c)(7)(i)(C) of Rule 2-01 of Regulation S-X.

(f) No disclosures are required by this Item 4(f).

(g) $24,015 and $13,213 are the aggregate non-audit fees billed in each of the last two fiscal years for services rendered by the principal accountant to the registrant. $0 and $0 are the aggregate non-audit fees billed in each of the last two fiscal years for services rendered by the principal accountant to the investment adviser or any entity controlling, controlled by or under common control with the adviser.

(h) No disclosures are required by this Item 4(h).

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

The registrant has a separately-designated standing audit committee. The members of the registrant’s audit committee are Joe F. Hanauer, Weston W. Marsh, John E. Neal, William R. Rybak, Stephen B. Timbers and David D. Tripple.

ITEM 6. SCHEDULE OF INVESTMENTS

Included in the Report to Shareholders in Item 1.

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED—END MANAGEMENT INVESTMENT COMPANIES.

The registrant has delegated authority to vote all proxies relating to the Fund’s portfolio securities to the Fund’s investment adviser, Calamos Advisors LLC (“Calamos Advisors”). The Calamos Advisors Proxy Voting Policies and Procedures are included as an Exhibit hereto.

ITEM 8. PORTFOLIO MANAGERS OF CLOSED—END MANAGEMENT INVESTMENT COMPANIES.

(a)(1) As of October 31, 2007, the registrant is lead by a team of investment professionals. The Co-Chief Investment Officers and senior strategy analysts are responsible for the day-to-day management of the registrant’s portfolio:

During the past five years, John P. Calamos, Sr. has been President and Trustee of the Fund and chairman, CEO and Co-CIO of the Fund’s investment adviser, Calamos Advisors LLC and its predecessor company (“Calamos Advisors”). Nick P. Calamos has been Vice President and Trustee of the Fund (through June 2006) and Senior Executive Vice President and Co-CIO of Calamos Advisors and its predecessor company. John P. Calamos, Jr., Executive Vice President of Calamos Advisors, joined the firm in 1985 and has held various senior investment positions since that time. John Hillenbrand joined Calamos Advisors in 2002 and has been a senior strategy analyst since August 2002. Steve Klouda joined Calamos Advisors in 1994 and has been a senior strategy analyst since July 2002. Jeff Scudieri joined Calamos Advisors in 1997 and has been a senior strategy analyst since September 2002. Jon Vacko joined Calamos Advisors in 2000 and has been a senior strategy analyst since July 2002.

(a)(2) The portfolio managers also have responsibility for the day-to-day management of accounts other than the registrant. Information regarding these other accounts is set forth below.

NUMBER OF OTHER ACCOUNTS MANAGED AND ASSETS BY ACCOUNT TYPE AS OF OCTOBER 31, 2007


	Registered				Other Pooled
	Investment				Investment				Other
	Companies				Vehicles				Accounts
	Accounts		Assets		Accounts		Assets		Accounts		Assets

John P. Calamos		22		35,149,492,739		4		297,610,723		22,371		11,308,779,683
Nick P. Calamos		22		35,149,492,739		4		297,610,723		22,371		11,308,779,683
John P. Calamos, Jr.		20		34,678,281,091		4		297,610,723		22,371		11,308,779,683
John Hillenbrand		19		33,129,883,529		3		242,155,204		22,371		11,308,779,683
Steve Klouda		19		33,129,883,529		3		242,155,204		22,371		11,308,779,683
Jeff Scudieri		19		33,129,883,529		3		242,155,204		22,371		11,308,779,683
Jon Vacko		19		33,129,883,529		3		242,155,204		22,371		11,308,779,683

NUMBER OF ACCOUNTS AND ASSETS FOR WHICH ADVISORY FEE IS PERFORMANCE BASED AS OF OCTOBER 31, 2007


	Registered				Other Pooled
	Investment				Investment				Other
	Companies				Vehicles				Accounts
	Accounts		Assets		Accounts		Assets		Accounts		Assets

John P. Calamos		1		565,845,779		2		148,730,762		0		—
Nick P. Calamos		1		565,845,779		2		148,730,762		0		—
John P. Calamos, Jr.		1		565,845,779		2		148,730,762		0		—
John Hillenbrand		1		565,845,779		1		93,275,243		0		—
Steve Klouda		1		565,845,779		1		93,275,243		0		—
Jeff Scudieri		1		565,845,779		1		93,275,243		0		—
Jon Vacko		1		565,845,779		1		93,275,243		0		—

The registrant’s portfolio managers are responsible for managing the registrant and other accounts, including separate accounts and unregistered funds.

Other than potential conflicts between investment strategies, the side-by-side management of both the Fund and other accounts may raise potential conflicts of interest due to the interest held by Calamos Advisors in an account and certain trading practices used by the portfolio managers (e.g., cross trades between a Fund and another account and allocation of aggregated trades). Calamos Advisors has developed policies and procedures reasonably designed to mitigate those conflicts. For example, Calamos Advisors will only place cross-trades in securities held by the Fund in accordance with the rules promulgated under the 1940 Act and has adopted policies designed to ensure the fair allocation of securities purchased on an aggregated basis.

The portfolio managers advise certain accounts under a performance fee arrangement. A performance fee arrangement may create an incentive for a portfolio manager to make investments that are riskier or more speculative than would be the case in the absence of performance fees. A performance fee arrangement may result in increased compensation to the

portfolio managers from such accounts due to unrealized appreciation as well as realized gains in the client’s account.

(a)(3) Calamos Advisors has developed and implemented a number of incentives that reward the professional staff to ensure that key employees are retained. Calamos Advisors’ senior management has established salary, short and long term incentive programs and benefit programs that we believe are competitive. Calamos Advisors’ incentive programs are based on investment performance, professional performance and an individual’s overall contribution. These goals and measures are established and reviewed on an annual basis during performance reviews. As of October 31, 2007, each portfolio manager receives compensation in the form of an annual base salary and a discretionary target bonus, each payable in cash. Their discretionary target bonus is set at a percentage of the respective base salary. The amounts paid to the portfolio managers and the criteria utilized to determine the amounts are benchmarked against industry specific data provided by a third party analytical agency. The compensation structure does not differentiate between the Funds and other accounts managed by the portfolio managers, and is determined on an overall basis, taking into consideration the performance of the various strategies managed by the portfolio managers. Portfolio performance, as measured by risk-adjusted portfolio performance, is utilized to determine the discretionary target bonus, as well as overall performance of Calamos Advisors. Portfolio managers are eligible to receive annual non-equity awards under a long term incentive compensation program, set at a percentage of the respective base salary.

(a)(4) As of October 31, 2007, the end of the registrant’s most recently completed fiscal year, the dollar range of securities beneficially owned by each portfolio manager in the registrant is shown below:


PORTFOLIO MANAGER		REGISTRANT

John P. Calamos, Sr.		over $1,000,000
Nick P. Calamos		none
John P. Calamos, Jr.		none
John Hillenbrand		none
Steve Klouda		none
Jeff Scudieri		none
Jon Vacko		none

(b) Not applicable.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

Not applicable.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

No material changes.

ITEM 11. CONTROLS AND PROCEDURES.

a) The registrant’s principal executive officer and principal financial officer have evaluated the registrant’s disclosure controls and procedures within 90 days of this filing and have concluded that the registrant’s disclosure controls and procedures were effective, as of that date, in ensuring that information required to be disclosed by the registrant in this Form N-CSR was recorded, processed, summarized, and reported timely.

b) There were no changes in the registrant’s internal controls over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

ITEM 12. EXHIBITS.

(a) (1) Code of Ethics

(a) (2) (i) Certification of Principal Executive Officer.

(a) (2) (ii) Certification of Principal Financial Officer.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.


Calamos Global Total Return Fund
By:	/s/ John P. Calamos, Sr.
	Name:	John P. Calamos, Sr.
	Title:	Principal Executive Officer
	Date:	December 27, 2007



By:	/s/ Nimish S. Bhatt
	Name:	Nimish S. Bhatt
	Title:	Principal Financial Officer
	Date:	December 27, 2007

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed by the following persons on behalf of the registrant and in the capacities and on the dates indicated.


Calamos Global Total Return Fund
By:	/s/ John P. Calamos, Sr.
	Name:	John P. Calamos, Sr.
	Title:	Principal Executive Officer
	Date:	December 27, 2007



By:	/s/ Nimish S. Bhatt
	Name:	Nimish S. Bhatt
	Title:	Principal Financial Officer
	Date:	December 27, 2007