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                        [MAYER, BROWN & PLATT LETTERHEAD]




                                 August 11, 2000


ProLogis Trust
14100 East 35th Place
Aurora, Colorado  80011

         Re:      Partnership Classification; Status as a Real
                  Estate Investment Trust ("REIT"); Information
                  in the Registration Statement under "FEDERAL
                  INCOME TAX CONSIDERATIONS"


Gentlemen:

         In connection with the filing of a Registration Statement with the
Securities and Exchange Commission on the date hereof (the "Registration
Statement"), by ProLogis Trust, a Maryland real estate investment trust (the
"Company"), you have requested our opinions concerning (i) the treatment of
ProLogis Limited Partnership-I, ProLogis Limited Partnership-II, ProLogis
Limited Partnership-III, and ProLogis Limited Partnership-IV (collectively, the
"Partnerships") as partnerships for Federal income tax purposes, and not as
associations taxable as corporations; (ii) the qualification and taxation of the
Company as a REIT; and (iii) the information in the Registration Statement under
the heading "FEDERAL INCOME TAX CONSIDERATIONS."

         In formulating our opinions, we have reviewed and relied upon the
partnership agreements of the Partnerships, the Registration Statement, such
other documents and information provided by you, and such applicable provisions
of law as we have considered necessary or desirable for purposes of the opinions
expressed herein.

         In addition, we have relied upon certain representations made by the
Company relating to the organization and actual and proposed operation of the
Company and the Partnerships. For purposes of our opinions, we have not made an
independent



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ProLogis Trust
August 11, 2000
Page 2

investigation of the facts set forth in such documents, representations from the
Company, the partnership agreements for the Partnerships or the Registration
Statement. We have, consequently, relied upon your representations that the
information presented in such documents or otherwise furnished to us accurately
and completely describes all material facts. We have also relied upon the
opinion of Vinson & Elkins L.L.P., dated March 30, 1999, with respect to the
qualification as a real estate investment trust of Meridian Industrial Trust,
Inc., a Maryland corporation, for its taxable years ending December 31, 1995,
1996, 1997, 1998 and its taxable year ending March 30, 1999.

         In rendering these opinions, we have assumed that the transactions
contemplated by the foregoing documents will be consummated in accordance with
the operative documents, and that such documents accurately reflect the material
facts of such transactions. In addition, the opinions are based on the
correctness of the following specific assumptions: (i) the Company and the
Partnerships have operated and will continue to each be operated in the manner
described in the applicable partnership agreement or other organizational
documents and in the Registration Statement, and all terms and provisions of
such agreements and documents have been and will continue to be complied with by
all parties thereto; and (ii) each partner in the Partnerships has been
motivated in acquiring its partnership interest by its anticipation of economic
rewards apart from tax considerations. Our opinions expressed herein are based
on the applicable laws of the States of Maryland and Delaware, the Code, the
Treasury regulations promulgated thereunder, and the interpretations of the Code
and such regulations by the courts and the Internal Revenue Service, all as they
are in effect and exist at the date of this letter. It should be noted that
statutes, regulations, judicial decisions, and administrative interpretations
are subject to change at any time and, in some circumstances, with retroactive
effect. A material change that is made after the date hereof in any of the
foregoing bases for our opinions, could adversely affect our conclusions.



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ProLogis Trust
August 11, 2000
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         Based upon and subject to the foregoing, it is our opinion that:

         1.  The Partnerships will be treated, for Federal income tax
purposes, as partnerships, and not as associations taxable as
corporations.

         2. Beginning with the Company's taxable year ending December 31, 1993,
the Company has been organized in conformity with the requirements for
qualification as a REIT under the Code, and the Company's actual and proposed
method of operation, as described in the Registration Statement and as
represented by the Company, has enabled it and will continue to enable it to
satisfy the requirements for qualification as a REIT.

         3. The information in the Registration Statement under the headings
"FEDERAL INCOME TAX CONSIDERATIONS," to the extent that it constitutes matters
of law or legal conclusions, has been reviewed by us and is correct in all
material respects.

         Other than as expressly stated above, we express no opinion on any
issue relating to the Company and the Partnerships or to any investment therein.

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the use of the name of our firm therein and under
the caption "FEDERAL INCOME TAX CONSIDERATIONS" in the Registration Statement.

                                       Very truly yours,



                                       /s/ MAYER, BROWN & PLATT