
<PAGE>   1
                                                                     EXHIBIT 8.1


                        [Letterhead of Latham & Watkins]







                                 April 9, 1999











AMB Property Corporation
505 Montgomery Street
San Francisco, California 94111

         Re:      AMB Property Corporation
                  Registration Statement on Form S-3

Ladies and Gentlemen:

                  We have acted as special counsel to AMB Property Corporation,
a Maryland corporation (the "Company"), in connection with the registration
statement on Form S-3 being filed by the Company on the date hereof with the
Securities and Exchange Commission in connection with the registration, under
the Securities Act of 1933, as amended, of 699,837 shares of the Company's
common stock, par value $.01 per share (together with all exhibits thereto and
documents incorporated by reference therein, the "Registration Statement").

                  In our capacity as such counsel, we have made such legal and
factual examinations and inquiries, including an examination of originals or
copies certified or otherwise identified to our satisfaction of such documents,
corporate records and other instruments, as we have deemed necessary or
appropriate for purposes of this opinion. In our examination, we have assumed
the authenticity of all documents submitted to us as originals, the genuineness
of all signatures thereon, 


<PAGE>   2
AMB Property Corporation
April 9, 1999
Page 2


the legal capacity of natural persons executing such documents and the
conformity to authentic original documents of all documents submitted to us as
copies.

                  We are opining herein as to the effect on the subject
transaction only of the federal income tax laws of the United States and we
express no opinion with respect to the applicability thereto, or the effect
thereon, of other federal laws, the laws of any state or other jurisdiction or
as to any matters of municipal law or the laws of any other local agencies with
any state.

                  Based upon the facts set forth in the Registration Statement,
it is our opinion that the information in the Registration Statement set forth
under the caption "Certain Federal Income Tax Considerations," to the extent
that it constitutes matters of law, summaries of legal matters, documents or
proceedings, or legal conclusions, has been reviewed by us and is correct in all
material respects.

                  No opinion is expressed as to any matter not discussed herein.

                  This opinion is only being rendered to you as of the date of
this letter, and we undertake no obligation to update this opinion subsequent to
the date hereof. This opinion is based on various statutory provisions,
regulations promulgated thereunder and interpretations thereof by the Internal
Revenue Service and the courts having jurisdiction over such matters, all of
which are subject to change either prospectively or retroactively. Also, any
variation or difference in the facts from those set forth in the Registration
Statement may affect the conclusions stated herein.

                  This opinion is rendered to you and is solely for your benefit
in connection with the Registration Statement. We hereby consent to the filing
of this opinion as an exhibit to the Registration Statement. This opinion may
not be relied upon by you for any other purpose, or furnished to, quoted to or
relied upon by any other person, firm or corporation for any purpose, without
our prior written consent.

                                       Very truly yours,


                                       /s/ LATHAM & WATKINS
