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                                                                     EXHIBIT 8.1


                               November ___, 1997




AMB Property Corporation
505 Montgomery Street
San Francisco, California 94111

      Re:   Registration Statement on Form S-11 (File No. 333-35915)
            Federal Income Tax Consequences

Ladies and Gentlemen:

            We have acted as tax counsel to AMB Property Corporation, a Maryland
corporation (the "Company"), in connection with its sale of up to 11,905,000
shares of common stock of the Company pursuant to a registration statement on
Form S-11 under the Securities Act of 1933, filed with the Securities and
Exchange Commission on November ___, 1997, (file number 333-35915) as amended as
of the date hereof (the "Registration Statement").

            You have requested our opinion concerning certain of the Federal
income tax consequences to the Company and the purchasers of the securities
described above in connection with the sale described above. This opinion is
based on various facts and assumptions, including the facts set forth in the
Registration Statement concerning the business, properties and governing
documents of the Company and AMB Property, L.P. (the "Operating Partnership").
We have also been furnished with, and with your consent have relied upon, (i)
certain representations made by the Company and the Operating Partnership with
respect to certain factual matters through a certificate of an officer of the
Company (the "Officer's Certificate"), (ii) certain representations made by AMB
Institutional Realty Advisors, Inc., a California corporation ("AMBIRA"), with
respect to certain factual matters through a certificate of an officer of AMBIRA
(the "AMBIRA Officer's Certificate"), and (iii) certain representations made by
AMB Current Income Fund, Inc., a Maryland corporation ("CIF"), AMB Value Added
Fund, Inc., a Maryland corporation ("VAF"), and Western Properties Fund-I, a
California limited partnership ("WPF"), as set forth in Exhibit I to that
certain Joint Proxy Statement/Offering Memorandum/Consent Solicitation dated as
of July 17, 1997 (the "Proxy"). With respect to certain matters relating to CIF
and VAF (and their successors), we have relied upon the opinion of Morrison &
Foerster, counsel to CIF and 


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AMB Property Corporation
November ___, 1997
Page 2

VAF (and such successors), dated November ___, 1997. With respect to certain
legal matters relating to Maryland law, we have relied upon the opinion of
Ballard Spahr Andrews & Ingersoll, counsel for the Company, dated November ___,
1997. With respect to matters relating to the tax status of certain shareholders
of AMBIRA, we have relied upon the opinion of Farella Braun & Martel LLP, 
counsel for such shareholders, dated November __, 1997.

            In our capacity as tax counsel to the Company, 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, 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 within any
state.

            Based on such facts, assumptions and representations, it is our
opinion that:

            1. Commencing with the Company's taxable year ending December 31,
1997, the Company will be organized in conformity with the requirements for
qualification as a "real estate investment trust" under the Internal Revenue
Code of 1986, as amended (the "Code"), and its proposed method of operation, as
described in the representations of the Company and the Operating Partnership
referred to above, will enable the Company to meet the requirements for
qualification and taxation as such a real estate investment trust.

            2. The Operating Partnership will be treated as a partnership for
Federal income tax purposes (and not as an association or publicly traded
partnership taxable as a corporation).

            3. Commencing with AMBIRA's taxable year ending December 31, 1989,
AMBIRA has qualified for taxation as an "S corporation" (as such term is defined
in Section 1361(a)(1) of the Code) for Federal income tax purposes and will
continue to so qualify through the date of its revocation of its election to be
taxed as an S corporation as a part of the Formation Transactions (as such term
is defined in the Registration Statement).

            4. The statements in the Registration Statement set forth under the
caption "Federal Income Tax Consequences" to the extent such information
constitutes matters of law, summaries of legal matters, or legal conclusions,
have been reviewed by us and are accurate in all material respects.


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AMB Property Corporation                                                   
November ___, 1997
Page 3

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

            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 representations described
above, including in the Registration Statement, the Officer's Certificate, or
the AMBIRA Officer's Certificate, may affect the conclusions stated herein.
Moreover, the Company's qualification and taxation as a real estate investment
trust depends upon the Company's ability to meet (through actual annual
operating results, distribution levels and diversity of stock ownership) the
various qualification tests imposed under the Code, the results of which have
not been and will not be reviewed by Latham & Watkins. Accordingly, no assurance
can be given that the actual results of the Company's operation for any one
taxable year will satisfy such requirements.

            This opinion is rendered only to you, and is solely for your use and
the use of your shareholders in connection with the transactions set forth in
the Registration Statement. This opinion may not be relied upon by you or your
shareholders 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. We hereby consent to the filing of this opinion as an exhibit
to the Registration Statement and to the use of our name under the caption
"Legal Matters" in the Registration Statement.

                               Very truly yours,
