SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549



                             -----------------------



                                    FORM 8-K



                                 CURRENT REPORT
                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934



       Date of Report (Date of earliest event reported): December 31, 2001



                         SENIOR HOUSING PROPERTIES TRUST
               (Exact name of registrant as specified in charter)




          Maryland                   001-15319                04-3445278
(State or other jurisdiction        (Commission            (I.R.S. employer
     of incorporation)              file number)        identification number)




400 Centre Street, Newton, Massachusetts                               02458
(Address of principal executive offices)                             (Zip code)




        Registrant's telephone number, including area code: 617-796-8350





         STATEMENTS CONTAINED IN THIS FORM 8-K THAT ARE NOT HISTORICAL FACTS ARE
FORWARD-LOOKING   STATEMENTS  WITHIN  THE  MEANING  OF  THE  PRIVATE  SECURITIES
LITIGATION  REFORM  ACT  OF  1995.  THESE  FORWARD-LOOKING   STATEMENTS  INCLUDE
REFERENCES  TO THE MINIMUM RENT EXPECTED TO BE RECEIVED BY US FROM THE LEASES OF
THE REFERENCED PROPERTIES TO FIVE STAR AND TO MARRIOTT'S CONTINUED MANAGEMENT OF
THE 31 PROPERTIES WHICH WE HAVE ACQUIRED.  THESE FORWARD-LOOKING  STATEMENTS ARE
BASED UPON OUR CURRENT BELIEFS AND EXPECTATIONS,  BUT THEY ARE NOT GUARANTEED TO
OCCUR.  FOR EXAMPLE,  FIVE STAR MAY BECOME  UNABLE TO PAY ITS  CONTRACTUAL  RENT
OBLIGATIONS  BECAUSE THE LEASED PROPERTIES DO NOT PRODUCE THE EXPECTED INCOME OR
FOR OTHER REASONS AND MARRIOTT MAY CEASE TO MANAGE THE 31 PROPERTIES WE ACQUIRED
BECAUSE IT SELLS ITS SENIOR LIVING MANAGEMENT BUSINESS OR FOR OTHER REASONS. THE
INFORMATION  CONTAINED  IN OUR ANNUAL  REPORT ON FORM 10-K FOR OUR  FISCAL  YEAR
ENDED   DECEMBER  31,  2000   INCLUDING   UNDER  THE  HEADINGS   "BUSINESS"  AND
"MANAGEMENT'S  DISCUSSION  AND  ANALYSIS OF FINANCIAL  CONDITION  AND RESULTS OF
OPERATIONS"  IDENTIFY OTHER IMPORTANT  FACTORS THAT COULD CAUSE SUCH DIFFERENCES
FROM OUR CURRENT BELIEFS OR  EXPECTATIONS.  INVESTORS ARE CAUTIONED NOT TO PLACE
UNDUE RELIANCE UPON THESE FORWARD-LOOKING STATEMENTS.

Item 2.    Acquisition or Disposition of Assets.

         On January 11, 2002, we and Crestline Capital Corporation ("Crestline")
closed the previously reported  transactions  contemplated by the Stock Purchase
Agreement (the "Stock Purchase  Agreement"),  dated as of August 9, 2001,  among
Crestline,  CSL Group,  Inc.,  us and one of our  subsidiaries.  Under the Stock
Purchase  Agreement,  our subsidiary  acquired 31 senior living communities from
Crestline  through the acquisition of the capital stock of CSL Group, Inc. Those
properties and the acquisition are more fully described in Item 5 of our Current
Report on Form 8-K dated  September  21,  2001,  as updated as set forth in this
Current Report.

         The total consideration paid to Crestline to acquire the 31 communities
was  approximately  $600 million and was comprised of: (i) the payment of $458.6
million in cash (which included a $7.5 million  deposit  released from an escrow
account),  (ii) the  issuance of our $25 million  unsecured  promissory  note to
Crestline due January 31, 2004, and (iii) our subsidiaries' assumption of $116.4
million of existing  indebtedness.  On January 24, 2002, we repaid $92.4 million
of the assumed debt with cash on hand and a drawing under our  revolving  credit
facility,  which reduced our secured  indebtedness  from this transaction to $24
million (excluding amounts outstanding under our revolving credit facility).

         The purchase  price was funded in part from (i) the net  proceeds  from
our issuance of 14 million common shares of beneficial interest for $181 million
in October  2001,  (ii) the net proceeds  from our issuance of $245 million of 8
5/8% Senior  Notes Due 2012 in December  2001 and (iii) a $120  million  drawing
under our  revolving  credit  facility  with  Dresdner  Bank AG,  as agent,  and
institutional  lenders.  Immediately after giving effect to such drawing and the
repayment of the assumed debt described above, the amount  outstanding under our
revolving credit facility was $196 million.


         The assets we acquired  from  Crestline  and its  subsidiaries  consist
principally of real property and related personal property used in its operation
of the 31 senior living  communities.  As more fully  described  under Part C of
Item 5 below, we have leased the acquired assets to Five Star Quality Care, Inc.
("Five Star") on a net lease basis in accordance  with our  previously  reported
Transaction Agreement.  The Transaction Agreement was entered into in connection
with the spin-off of Five Star referred to in Part A of Item 5 below.

Item 5.  Other Events.

         A.       SPIN-OFF

         We have previously  reported our proposed spin-off of Five Star, one of
our wholly owned  subsidiaries.  On December 31, 2001, we completed the spin-off
by  distributing  4,342,170  shares  of Five  Star  common  stock to our  common
shareholders. The distribution was one share of Five Star common stock for every
10 of our common shares owned.  Following  completion of the Five Star spin-off,
we continue to own 35,000 shares of Five Star common stock.

         On  January  2,  2002,  Five Star  completed  its  previously  reported
acquisition  of FSQ,  Inc.,  formerly  known as Five  Star  Quality  Care,  Inc.
("FSQ"),  in order for Five Star to acquire  the  personnel,  systems and assets
necessary  to operate  the 56  facilities  which Five Star  leases  from us. The
consideration  for this  merger was  125,000  shares of Five Star  common  stock
payable  to each of Gerard M.  Martin and Barry M.  Portnoy,  the owners of FSQ.
Messrs.  Martin and Portnoy are our managing  trustees.  In connection  with the
merger,  our Board of  Trustees  received  an  opinion  from an  internationally
recognized  investment  banking firm to the effect that,  as of December 5, 2001
(the date of the related merger  agreement),  the consideration  provided for in
the merger was fair, from a financial point of view, to Five Star.

         B.       COMMENCEMENT OF LEASE FOR 56 PROPERTIES

         In connection  with the  consummation  of the spin-off of Five Star, we
and Five Star have entered into a lease for 56 facilities which are described in
Item 5 of our Current Report on Form 8-K dated September 21, 2001.

         The lease is an obligation of a subsidiary of Five Star,  and the lease
described in Part C below is an  obligation  of two  subsidiaries  of Five Star.
Each lease has been  guaranteed by Five Star.  (References  below in this Part B
and in Part C to Five Star  include both Five Star and such  subsidiaries.)  The
following is a summary of the material terms of the lease for the 56 facilities:

         Operating  Costs.  The lease is a  so-called  "triple-net"  lease which
requires Five Star to pay all costs incurred in the operation of the facilities,
including  the costs of  personnel,  service to  residents,  insurance  and real
estate and personal property taxes.

         Minimum Rent. The lease requires Five Star to pay minimum rent to us in
an amount equal to $7 million per year.

                                      -2-


         Percentage  Rent.  Starting in 2004, the lease will require  additional
rent with respect to each lease year in an amount equal to three percent (3%) of
net patient  revenues at each leased facility in excess of net patient  revenues
at such facility during 2003.

         Term. The lease expires on December 31, 2018.

         Renewal  Option.  Five Star will have the option to renew the lease for
all,  but not less than all, of the  facilities  for one renewal  term ending on
December 31, 2033. Five Star may not exercise this renewal option unless it also
exercises the renewal  option under the lease that we and Five Star entered into
relating to the 31  communities we acquired from Crestline and its subsidiary as
more fully described under Part C below.

         Rent During  Renewal  Term.  Rent  during the  renewal  term shall be a
continuation  of minimum rent and  percentage  rent  payable  during the initial
term.

         Maintenance and Alterations.  Five Star is required to maintain, at its
expense,  the leased communities in good order and repair,  including structural
and  nonstructural  components.  Five Star may request us to fund amounts needed
for  repairs  and  renovations  in return for rent  adjustments  to provide us a
return on our investment  according to a formula set forth in the lease.  At the
end of the lease term, Five Star is required to surrender the leased  facilities
in substantially  the same condition as existed on the commencement  date of the
lease,  subject to any  permitted  alterations  and subject to ordinary wear and
tear.

         Assignment and  Subletting.  Our consent is generally  required for any
direct or indirect assignment or sublease of any of the facilities. In the event
of any assignment or subletting, Five Star will remain liable under the lease.

         Environmental Matters. Five Star is required, at its expense, to remove
and dispose of any  hazardous  substance at the leased  facilities in compliance
with  all  applicable   environmental  laws  and  regulations.   Five  Star  has
indemnified us for any liability  which may arise as a result of the presence of
hazardous  substances at any leased facilities and from any violation or alleged
violation of any applicable environmental law or regulation.

         Indemnification and Insurance.  With limited  exceptions,  Five Star is
required to indemnify us from all liabilities which may arise from the ownership
or operation  of the  facilities.  Five Star is  generally  required to maintain
commercially  reasonable  insurance.   That  insurance  initially  includes  the
following types:

     o    "all-risk" property insurance,  in an amount equal to 100% of the full
          replacement cost of the facilities;

     o    business interruption insurance;

     o    comprehensive general liability insurance, including bodily injury and
          property damage,  in amounts as are generally  maintained by companies
          providing senior living services;

     o    flood  insurance  if any  facility is located in whole or in part in a
          flood plain;

                                      -3-


     o    worker's compensation insurance if required by law; and

     o    such additional  insurance as may be generally maintained by companies
          providing senior living services.

The  lease  requires  that we be  named as an  additional  insured  under  these
policies.

         Damage, Destruction or Condemnation. If any of the leased facilities is
damaged  by fire or other  casualty  or taken  for a public  use,  Five  Star is
generally  obligated to rebuild unless the facility  cannot be restored.  If the
facility cannot be restored,  we will generally  receive all insurance or taking
proceeds  and Five  Star is liable to us for the  amount  of any  deductible  or
deficiency between the replacement cost and the insurance proceeds.

         Events of  Default.  Events of  default  under  the lease  include  the
following:

     o    Five Star's failure to pay rent or any other sum when due;

     o    Five  Star's  failure to maintain  the  insurance  required  under the
          lease;

     o    the  occurrence of certain  events of insolvency or  dissolution  with
          respect to Five Star;

     o    any person or group of affiliated persons acquiring  ownership of more
          than 9.8% of Five Star's voting stock or any change of control or sale
          of a material portion of Five Star's assets without our consent;

     o    a cross  default  relating  to the Five Star lease with us relating to
          the 31  communities  we  acquired  from  Crestline  and to  Five  Star
          indebtedness;

     o    Five Star being  declared  ineligible to receive  reimbursement  under
          Medicare or Medicaid programs for any of the leased facilities; and

     o    Five Star's  failure to perform any terms,  covenants or agreements of
          the lease and the continuance  thereof for a specified  period of time
          after written notice.

         Default  Remedies.  Upon the  occurrence  of any event of default,  the
lease provides that we may (subject to applicable law):

     o    terminate the lease and accelerate the rent;

     o    terminate the tenant's rights to occupy and use the leased facilities,
          relet the leased  facilities and recover from Five Star the difference
          between  the amount of rent which  would have been due under the lease
          and the rent received under the reletting;

     o    terminate any other lease which Five Star has with us;

     o    exercise rights with respect to any collateral securing the lease; and

                                      -4-


     o    make any payment or perform any act  required to be  performed by Five
          Star under the lease.

We have the  right to  require  Five  Star to  reimburse  us for all  costs  and
expenses incurred in connection with any exercise of the foregoing remedies.

         C.       COMMENCEMENT OF LEASE FOR 31 PROPERTIES

         Pursuant to the  previously  reported  Transaction  Agreement,  we have
leased  to Five Star the 31  communities  we  acquired  from  Crestline  and its
subsidiary.  The  31  communities  are  managed  by  a  subsidiary  of  Marriott
International,  Inc. ("Marriott").  The material terms of our lease arrangements
for these 31 communities  are  substantially  the same as those of our lease for
the 56 facilities described above in Part B, except as follows:

         Minimum Rent. The lease requires Five Star to pay minimum rent to us of
$63 million per year.

         Percentage Rent.  Starting in 2003, the lease requires  additional rent
with  respect to each lease year in an amount  equal to five percent (5%) of net
patient  revenues at each leased  facility in excess of net patient  revenues at
such facility during 2002.

         FF&E Reserves.  Five Star is required to maintain  accounts for capital
replacements and improvements.

         Term. The lease expires on December 31, 2017.

         Renewal  Options.  Five Star has two options to renew the lease for all
but not less than all of the communities: the first for 10 years ending December
31, 2027; and the second for five years ending  December 31, 2032. Five Star may
not exercise  these renewal  options  unless Five Star has exercised its renewal
option under the lease for the 56  facilities.  The first renewal option must be
exercised by notice to us two years prior to the expiration of the initial term.
The second  renewal  option must be exercised by notice to us at least 11 months
before the then current term expires.

         Events of Default. In addition to the events of default described under
our lease for the 56 facilities  described above in Part B, the lease for the 31
communities includes the following events of default:

     o    Five Star's default under any Marriott management agreement; and

     o    Five Star or any of its subsidiaries'  default under the lease for the
          other 56 facilities.

         D.       RESIGNATION AND ELECTION OF TRUSTEE

         In connection  with the Five Star spin-off,  Dr. Bruce M. Gans resigned
as a member of our Board of Trustees  effective  December  31, 2001 and became a
director of Five Star,  creating a vacancy on our Board. On January 9, 2002, our
Board of  Trustees  elected  Frank J.  Bailey to the  Board to fill the  vacancy
created by Dr. Gans'  resignation.  Mr. Bailey is a Group I Trustee

                                      -5-


and his term continues until our 2003 Annual Meeting of Shareholders. Mr. Bailey
has been a partner in the  Boston  law firm  Sherin & Lodgen LLP during the past
five years, and he focuses his practice in business litigation.

Item 7.  Financial Statements, Pro Forma Financial Information and Exhibits.

         (b)      Pro  Forma  Financial  Information.  The pro  forma  financial
                  information  required  by Item  7(b) is  omitted  pursuant  to
                  General  Instruction  B.3 to Form 8-K. The pro forma financial
                  information required by Item 7(b) has been previously reported
                  by Senior  Housing  Properties  Trust in its Current Report on
                  Form 8-K dated December 20, 2001.

         (c)      Exhibits.

2.1  Stock Purchase  Agreement dated as of August 9, 2001,  among Senior Housing
     Properties Trust,  SNH/CSL Properties Trust,  Crestline Capital Corporation
     and CSL Group,  Inc.,  including forms of Promissory Note, Escrow Agreement
     and Tax Allocation  Agreement  (Incorporated by reference to Senior Housing
     Properties Trust's Current Report on Form 8-K dated September 21, 2001).

2.2  Amendment  to Stock  Purchase  Agreement  among Senior  Housing  Properties
     Trust,  SNH/CSL  Properties Trust,  Crestline  Capital  Corporation and CSL
     Group,  Inc.  dated November 5, 2001  (Incorporated  by reference to Senior
     Housing  Properties  Trust's  Current  Report on Form 8-K dated November 5,
     2001).

10.1 Master Lease  Agreement by and among certain  affiliates of Senior  Housing
     Properties Trust, as Landlord, and Five Star Quality Care Trust, as Tenant,
     dated December 31, 2001.

10.2 Guaranty Agreement made by Five Star Quality Care, Inc., as Guarantor,  for
     the benefit of certain  affiliates of Senior Housing Properties Trust dated
     December  31,  2001,  relating  to the Maser Lease  Agreement  by and among
     certain  affiliates of Senior Housing  Properties  Trust, as Landlord,  and
     Five Star Quality Care Trust, as Tenant, dated December 31, 2001.

10.3 Amended  Master Lease  Agreement by and among certain  affiliates of Senior
     Housing Properties Trust, as Landlord,  and FS Tenant Holding Company Trust
     and FS Tenant Pool III Trust, as Tenant, dated January 11, 2002.

10.4 Guaranty Agreement made by Five Star Quality Care, Inc., as Guarantor,  for
     the benefit of certain  affiliates of Senior Housing Properties Trust dated
     January 11, 2002,  relating to the Amended  Master  Lease  Agreement by and
     among certain  affiliates of Senior Housing  Properties Trust, as Landlord,
     and FS  Tenant  Holding  Company  Trust and FS Tenant  Pool III  Trust,  as
     Tenant, dated January 11, 2002.

                                      -6-



                                   SIGNATURES

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

                                          SENIOR HOUSING PROPERTIES TRUST


                                          By:  /s/ David J. Hegarty
                                              Name:   David J. Hegarty
                                              Title:  President, Chief Operating
                                                      Officer  and Secretary



Date:  January 24, 2002