Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
PORTNOY BARRY M
  2. Issuer Name and Ticker or Trading Symbol
SENIOR HOUSING PROPERTIES TRUST [NYSE: SNH]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O REIT MANAGEMENT & RESEARCH LLC, 400 CENTRE STREET
3. Date of Earliest Transaction (Month/Day/Year)
04/11/2008
(Street)

NEWTON, MA 02458
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Shares of Beneficial Interest 04/11/2008   J(1)   15,020 A $ 23.43 (2) 36,327 D  
Common Shares of Beneficial Interest               108,009 I See Footnote (3)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
PORTNOY BARRY M
C/O REIT MANAGEMENT & RESEARCH LLC
400 CENTRE STREET
NEWTON, MA 02458
  X      

Signatures

 /s/ Barry M. Portnoy   04/11/2008
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) These shares were issued pursuant to an Advisory Agreement between the issuer and Reit Management & Research LLC ("RMR"), of which Mr. Portnoy is a director and majority beneficial owner. Mr. Portnoy purchased these shares from RMR upon their issuance. Such transfers were exempt from Section 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), pursuant to Rule 16a-13 thereunder.
(2) In accordance with the Advisory Agreement referred to above, certain historical share price information was used to determine the number of common shares of beneficial interest paid to RMR. The per share price amount listed above is the closing sale price of the issuer's common shares of beneficial interest on the New York Stock Exchange on April 11, 2008, when the shares were issued and purchased.
(3) 68,990 of such shares are held by Portnoy Family Corporation, a corporation of which Mr. Portnoy is the sole shareholder. 39,019 of such shares are held by RMR. Mr. Portnoy disclaims beneficial interest of the shares held by RMR except to the extent of his pecuniary interest therein.

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