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                                                                     EXHIBIT 4.5

                           SUPPLEMENTARY AGREEMENT TO
                  COMPREHENSIVE PRODUCTS AND SERVICES AGREEMENT

      This Supplementary Agreement to Comprehensive Products and Services
Agreement (this "Supplementary Agreement") is executed this 9th day of June,
2005 in Beijing by and between the following two parties through their
respective authorized representatives:

      (1) China National Petroleum Corporation ("CNPC"), a state-owned
enterprise duly established and existing under the laws of the People's Republic
of China (the "PRC"), with its enterprise legal person business license number
being 1000001001043 and registered address being at Liupukang, Xicheng District,
Beijing; and

      (2) PetroChina Co., Ltd. ("PetroChina"), a joint stock limited company
duly established and existing under the laws of the PRC, with its enterprise
legal person business license number being 1000001003252 and registered address
being at 16 Andelu, Dongcheng District, Beijing.

      WHEREAS,

      1. PetroChina is a company incorporated under the laws of the PRC and its
H shares and the American Depositary Shares are currently listed and traded on
the Stock Exchange of Hong Kong Limited and on the New York Stock Exchange, Inc.
respectively. PetroChina shall, therefore, comply with the laws of the PRC and
of the jurisdictions in which its shares are listed in the conduct of its
operations and other business activities.

      2(pound)(R)CNPC and PetroChina executed the Comprehensive Products and
Services Agreement dated March 10, 2000 (the "Master Agreement"), whereby, CNPC
and PetroChina shall, and shall agree to cause their respective subsidiaries,
branches and other controlled entities to, provide relevant products and
services to each other pursuant to relevant provisions therein.

      3. PetroChina intends to increase registered capital of Zhong You Kan Tan
Kai Fa Co., Ltd. (the "Zhong You Kan Tan"), indirectly 100% owned subsidiary of
CNPC, so as to acquire 50% of the equity interest in Zhong You Kan Tan. For the
purpose thereof, PetroChina and CNPC have agreed to make amendments to the
Master Agreement, which shall constitute a supplementary agreement thereto.

      4. Both parties hereby agree to, and warrant that they will cause their
respective subsidiaries, branches and any other controlled entities to, provide
relevant products and services to each other both within and outside of the PRC
pursuant to the terms and principles set forth in the Master Agreement and this
Supplementary Agreement.

Now, therefore, the parties hereto reach agreement as follows:

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                                    ARTICLE 1

      CNPC and PetroChina agree that the Master Agreement shall be amended as
follows:

      1. "Government-Set-Price" shall mean the price for such type of services
as determined in any laws, regulations, decisions, orders or guidelines enacted
by any government of the relevant country/region (including but not limited to
any central government, federal government, local government, state/league
government, and any other instrumentality that rules a certain territory by
controlling domestic issues and foreign affairs thereof, in whatever name,
structure and form), and any other regulatory authority.

      2. "Market Price" shall mean the price determined according to the
following order of priority:

      (i)   the price then charged by independent third parties providing such
            type of services at arm's length in the region where such type of
            services is provided; or

      (ii)  the price then charged by independent third parties providing such
            type of services at arm's length in the regions/ countries near the
            region where such type of services is provided.

      3. This Supplementary Agreement shall be effective for a term of three (3)
years, commencing from the date on which this Supplementary Agreement comes into
effect. The Master Agreement shall remain effective during the term hereof and
shall expire simultaneously with the expiration of the Supplementary Agreement.

                                    ARTICLE 2

      This Supplementary Agreement shall constitute amendments and supplements
to the Master Agreement. Any matters not covered hereunder shall be governed by
the Master Agreement. In case of any discrepancy between this Supplementary
Agreement and the Master Agreement, this Supplementary Agreement shall prevail.

                                    ARTICLE 3

      This Supplementary Agreement shall come into effect after being executed
by the authorized representatives of both parties hereto and approved by the
shareholders' general meeting of PetroChina and PetroChina having become the
shareholder of Zhong You Kan Tan.

                                    ARTICLE 4

      IN WITNESS WHEREOF, both parties have caused this Supplementary Agreement
to be executed at the date written on the first page above.

                                       -2-
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CHINA NATIONAL PETROLEUM CORPORATION (company seal)

By: /s/ Zhou Jiping
    ----------------------------

PETROCHINA CO., LTD. (Company)

By: /s/ Wang Guoliang
    ----------------------------

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