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                                                                     EXHIBIT 4.3

                        SECOND SUPPLEMENTAL AGREEMENT TO

                  COMPREHENSIVE PRODUCTS AND SERVICES AGREEMENT

     This Supplemental Agreement to Comprehensive Products and Services
Agreement (this "Supplemental Agreement") is executed on September 1(st), 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 (the "HKSE") and on the New York Stock
Exchange, Inc. respectively, thereby, PetroChina shall 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. 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. CNPC and PetroChina executed the First Supplemental Agreement to
Comprehensive Products and Services Agreement (the "First Supplemental
Agreement") on June 9, 2005, which amended certain terms of the Master
Agreement. According to the agreement in the First Supplemental Agreement, the
First Supplemental Agreement came into effect upon (i) the execution by the duly
authorized representatives of both parties, (ii) the approval of the
shareholders' meeting of PetroChina, and (iii) PetroChina becoming the
shareholder of Zhong You Kan Tan Kai Fa Company Limited ("NewCo");

     4. As per the demands for the development of the business of PetroChina,
and the provisions in the HKSE Listing Rules ("Listing Rules"), the two parties
shall make corresponding amendments and supplements to the Master Agreement;

     5. The two parties hereby agree to provide and shall procure their
respective entities, including their subsidiaries, branches and other relevant
units, to provide products and services to each other both at home and abroad in
accordance with the terms and

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principles of the Master Agreement, the First Supplemental Agreement and this
Supplemental Agreement.

NOW THEREFORE, the two parties enter into the following agreement:


                                    ARTICLE 1

The two parties agree to make the following amendments to the Master Agreement:

     1. The sixth paragraph of the Background of the Master Agreement shall be
amended as follows:

"On such basis, Party A and Party B are willing to sign this Agreement, and
provide each other with the relevant products and services pursuant to this
Agreement. Therefore, both parties agree and guarantee to procure their
respective entities, including their respective subsidiaries, branches and other
relevant units, to provide the products and services hereof in accordance with
the terms and principles of this Agreement;"

     2. Section 5.1(a) (ii) of the Master Agreement shall be amended as follows:

"Party A has the right to receive, including through its entities (including its
subsidiaries, branches and other relevant units) fees pursuant to the provision
of this Agreement;"

     3. Section 5.1(b) (i) of the Master Agreement shall be amended as follows:

"to procure and guarantee its entities, including its subsidiaries, branches and
other relevant units, to enter into the relevant products and services
implementation agreements with Party B and its entities, including its
subsidiaries, branches and other related units thereof, pursuant to the
provisions of this Agreement and the annual service demand and supply plans;"

     4. Section 5.1(b) (vi) of the Master Agreement shall be amended as follows:

"to procure its entities, including its subsidiaries, branches and other
relevant units, to provide relevant services to Party B and its entities,
including its subsidiaries, branches and other relevant units, and guarantee to
indemnify Party B or the corresponding parties against any loss suffered by the
same arising from any breach of any provision of this Agreement or the relevant
product and service implementation agreements;"

     5. Section 5.2(a)(i) of the Master Agreement shall be amended as follows:

"Party B has the right to obtain, including through its entities (including its
subsidiaries, branches and other relevant units), the services provided by Party
A.;"

     6. Section 5.2(a) (iv) of the Master Agreement shall be amended as follows:

"to receive, including through its entities (including its subsidiaries,
branches and other relevant units), the fees for services pursuant to this
Agreement;"

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     7. Section 5.2(b) (i) of the Master Agreement shall be amended as follows:

"to procure and guarantee its entities, including its subsidiaries, branches and
other relevant units, to enter into the relevant product and service
implementation agreements with Party B and its entities, including its
subsidiaries, branches and other related units thereof, pursuant to the
provisions this Agreement and the supply and demand plan;"

     8. Section 1.2(a) of the Master Agreement shall be amended as follows by
inserting such item as "risk operation services" therein as part of the
construction and technical services:

"Construction and technical services: geophysical surveying, drilling,
well-cementing, logging, mud logging, well testing, downhole operation, oilfield
construction (including construction and installation), oil refinery
construction (including construction and installation), engineering and design,
project monitoring and management, equipment repairing and maintenance,
equipment antiseptic testing and technology research (including the service of
patent, know-how and computer software provided for the aforesaid service),
information service, public construction (the road of oil fields and factories,
municipal construction, civil buildings and public facilities), risk operation
services and other relevant or similar services".

     9. Article 1 of the Master Agreement shall be amended by adding the
following paragraph thereto as Section 1.4:

"Party B shall provide financial assistance to those companies jointly owned by
Party A and Party B in which Party A and its subordinate companies and entities
(including subsidiaries, branches and other entities) hold 10% or more of the
voting securities, whether individually or in the aggregate, (hereinafter
referred to as "Jointly-owned Companies"), including (a) the provision of
entrusted loans to the Jointly-owned Companies through China National Petroleum
Company Finance Co., Ltd. or other financial institutions, and (b) the provision
of guarantee for the Jointly-owned Companies."

     10. Article 1 of the Master Agreement shall be amended by adding the
following paragraph thereto as Section 1.5:

"The Jointly-owned Companies shall provide financial assistance to Party B,
including (a) the provision of entrusted loans to Party B through China National
Petroleum Company Finance Co., Ltd. or other financial institutions, and (b) the
provision of guarantee for Party B."

     11. Article 1 of the Master Agreement shall be amended by adding the
following paragraph thereto as Section 1.6:

"Products provided by Jointly-owned Companies include: crude oil, oil products,
chemical products, and natural gas etc. Pricing standards for the foregoing
products shall refer to the pricing standards of the same services as listed in
Appendix 1 of the Master Agreement."

     12. Article 3 of the Master Agreement shall be amended by adding the
following paragraph thereto as Section 3.3:

"(a) Pricing standards of the various financial assistance provided by Party B
to Jointly-

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owned Companies shall refer to the pricing standards of the same services as
listed in the financial service category of Appendix II of the Master Agreement;
(b) Pricing standards of the various financial assistance provided by
Jointly-owned Companies to Party B shall refer to the pricing standards of the
same services as listed in the financial category of Appendix II of the Master
Agreement."

     13. Article 13 of the Master Agreement shall be amended by adding the
following definition of "risk operation services" after the definition of
"supply" in Section 13.1:

"Risk operation services: Within certain reserve blocks with exploitation
difficulties specified by Party B, Party A provides comprehensive risk operation
services to Party B for its exploitation and production within these reserve
blocks by supplying capital and bear the risks. Party B is responsible to pay a
service fee to Party A only when there are crude oil and natural gas outputs in
these reserve blocks. Such services are contractual services. The mineral
interests and ownership of reserves of such reserve blocks remain unchanged. The
outputs of crude oil and natural gas shall be recorded to Party B, who is
responsible for the centralized sales of such outputs. Taking into consideration
the quality level, the difficulties of exploitation, and the investment status
of the reserve blocks where Party A provides risk operation services, the
service fee paid by Party B shall be calculated based on a certain percentage of
the then prevailing market price of the crude oil and natural gas outputs under
the risk operation services Party A provided, and shall be paid in cash. The
service fee during the investment payback period shall be 60% - 70% of the then
prevailing market price of crude oil and gas, and shall be 50% of the then
prevailing market price of crude oil and gas after the investment payback period
expires."

     14. Appendix II of the Master Agreement shall be amended by adding Item 16
"risk operation services" to the category of project technologies and services,
the pricing standard is the "market price"; the original Item 16 (including
information services) shall become Item 17.

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

     16. In case of any discrepancy between this Supplemental Agreement and the
First Supplemental Agreement, this Supplemental Agreement shall prevail,
regardless of the effective date of the First Supplemental Agreement.

     17. This Supplemental 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 Supplemental
Agreement and the Master Agreement, this Supplemental Agreement shall prevail.

     ARTICLE 2 This Supplemental Agreement shall come into effect as of January
1, 2006 after being executed by the authorized representatives of both parties
hereto and approved by the shareholders' general meeting of PetroChina.

     ARTICLE 3 IN WITNESS WHEREOF, both parties have executed this Supplemental
Agreement at the date written on the first page above.

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CHINA NATIONAL PETROLEUM CORPORATION (COMPANY SEAL)



By: /s/ Wang Yilin
    ---------------------------
    Authorized Representative: Wang Yilin







PETROCHINA CO., LTD. (COMPANY SEAL)



By: /s/ Wang Guoliang
    --------------------------
    Authorized Representative: Wang Guoliang

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