Exhibit 5.1

 [LETTERHEAD OF GREENBERG GLUSKER FIELDS CLAMAN & MACHTINGER LLP APPEARS HERE]




                                        December 4, 1997



Capital Trust
605 Third Avenue
New York, New York 10016

      Re:  Form S-1 Registration Statement
           (Registration No. 333-37271)
           -------------------------------

Ladies and Gentlemen:

      At your request, we have examined the Registration Statement filed by 
Capital Trust, a California business trust (the "Trust"), on October 6, 1997, in
connection with the registration under the Securities Act of 1933, as amended, 
of Class A Common Shares of Beneficial Interest, par value $1.00 per share, as 
follows:

            (a) 8,000,000 shares (the "Shares"), which are authorized and 
unissued securities to be issued and sold in the manner set forth in said 
Registration Statement; and

            (b) 1,200,000 additional shares (the "Additional Shares"), which are
authorized and unissued shares subject to an overallotment option, as set forth 
in said Registration Statement.

      As California counsel for the Trust, we are familiar with the provisions 
of the Amended and Restated Declaration of Trust and the Bylaws of the Trust. In
addition, we have examined the Registration Statement and the proceedings taken 
by the Board of Trustees of the Trust in connection therewith. Based upon the 
foregoing and subject to the effectiveness of the Registration Statement prior 
to the sale of the Shares and the Additional Shares, we are of the opinion that,
when issued and sold in the manner set forth in the Registration Statement:






 
GREENBERG GLUSKER FIELDS
CLAMAN & MACHTINGER LLP


Capital Trust
December 4, 1997
Page 2


      1.   The Shares will be legally and validly issued and outstanding, fully 
paid and non-assessable.

      2.   To the extent that the overallotment option is exercised pursuant to 
the terms thereof, the Additional Shares with respect to which such option is 
exercised will be legally and validly issued and outstanding, fully paid and 
non-assessable.

      We hereby consent to the filing of this opinion as an Exhibit to the 
Registration Statement and to the use of our name therein and in the Prospectus 
which is a part thereof.


                                                Very truly yours,



                                                GREENBERG GLUSKER FIELDS
                                                CLAMAN & MACHTINGER LLP