Exhibit 4.21
  Assets Transfer Agreement
  China National Petroleum Corporation
  PetroChina Company Limited




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Assets Transfer Agreement
 th China National Petroleum Corporation Transferor PetroChina Company Limited Transferee
  (i)
    
    The Transferor and its affiliated entities propose to transfer the Target Assets
(as defined hereunder) which they legally and effectively own to The Transferee;
 (ii)
    
    The Transferor hereby agrees and warranties to cause its associated affiliated
entities to transfer the Target Assets (as defined hereunder) in accordance with the
terms agreed hereunder; and
 (iii)
    
    The Transferee desires to take delivery of the Target Assets (as defined
hereunder).
 the Contract Law of the Peoples Republic of China the Company Law of the
Peoples Republic of China
 Article 1
    
    Definitions
 1.1
    
    For the purposes of this Agreement, unless the context otherwise specifies, terms
in this Agreement shall have the meanings set forth below:
 CNPC
    
    refers to China National Petroleum Corporation;CNPC Affiliated 
Entities
    
    refers to the subsidiaries, branches and other entities under CNPC;PetroChina
    
    refers to PetroChina Company Limited;Target Assets
    
    refers to all the targets contemplated to be transferred under
Article 2 of this Agreement;Target Entities
    
    refers to the entities set out in Article 2.1 hereunder, the
equity interests of which are held by CNPC and/or CNPC Affiliated
Entities;The Transfer
    
    refers to the transfer of the Target Assets by the Transferor to
the Transferee hereunder.
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This Agreement
    
    refers to this Assets Transfer Agreement and all the exhibits
attached hereto. This Agreement or other similar terms refers to
this agreement in its entirety rather than any specific provisions
contained herein. This Agreement referred to hereunder at any
time also refers to this Assets Transfer Agreement and all the
exhibits attached hereto as supplemented and/or amended from time
to time;Valuer
    
    refers to China Enterprise Appraisal Co., Ltd., who has issued an
assets valuation report on the Target Assets for the purpose of
the Transfer contemplated hereunder;Valuation Date
    
    refers to:1. July 31, 2007, the date on which valuation was conducted on the
100% interest in Hebei Zhongyou Sales Company Limited held by
CNPC, BGP Inc. in PetroChina;2. August 31, 2007, the date on which appraisals were conducted on
the 100% interest in Beijing Huayou Petroleum Company Limited held
by China Huayou Group Corporation, the 100% interest in Tianjin
Huabei New Petroleum Technologies Development Enterprise General
Company held by China Huayou Group Corporation and the assets
associated with the Yizhuang Service Station owned by China
Petrochemical Company under China Huayou Group Corporation; and3. December 31, 2007, the date on which valuation was conducted on
the other Target Assets;Completion
    
    refers to the transfer of the Target Assets in accordance with
Article 5 hereof;Completion Date
    
    refers to the date on which all the conditions precedent specified
in Article 4 hereof have been satisfied and the Transferee has
paid the consideration regarding the Transfer; such date shall not
be later than thirty (30) business days following the fulfillment
of all the conditions precedent;Transit Period
    
    refers to the period from Valuation Date to the Completion Date;The P.R.C.
    
    the Peoples Republic of ChinaSASAC
    
    the State-owned Assets Supervision and Administration Commission
 Article 2
    
    Target Assets
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2.1
    
    The associated non-equity assets as set out in Exhibit 1 hereto.The Transferor agrees to transfer to the Transferee, and the Transferee agrees to
take delivery from the Transferor, the above associated non-equity assets in
accordance with the terms and conditions hereunder.
 2.2
    
    The associated equity as set out in Exhibit 2 hereto.The Transferor agrees to transfer to the Transferee, and the Transferee agrees to
take delivery from the Transferor, the above associated equity in accordance with
the terms and conditions hereunder.
 Article 3
    
    Consideration for Transfer of Assets
  Article 4
    
    Conditions Precedent for Delivery of the Target Assets
 The Completion of the Transfer hereunder shall be conducted on the Completion Date
determined by the parties hereto after all the following conditions of Completion
have been satisfied:
 4.1
    
    This Agreement has been duly signed by the legal representatives of the Transferor
and the Transferee or their respective authorized representative;
 4.2
    
    All necessary consents or approvals in connection with this Agreement and the
Target Assets have been obtained, including without limitation:
 (a)
    
    The Transferor has obtained approval from its board of
directors on the Transfer of assets, and has obtained commitment on the waiver
of the pre-emptive rights in connection with the associated equity from other
shareholders (if any);
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(b)
    
    The Transferee has obtained approval from its internal
competent authorities for its taking delivery of the assets from the
Transferor;
 (c)
    
    The valuation reports on which the Transfer consideration is
based have been confirmed by the Transferor and the Transferee and have been
duly filed with the SASAC;
 (d)
    
    Approval has been obtained from the SASAC for the Transfer of
the assets as contemplated hereunder.
 4.3
    
    As at the Completion Date, the Transferors representations, warranties and
covenants contained herein shall remain true and accurate.
  Article 5
    
    Delivery of the Target Assets
 5.1
    
    The Transferor shall, within a reasonable period, actively procure the fulfillment
of all the Completion conditions specified in Article 4 (other than 2.(2)) hereof, give a
notice to the Transferee in writing requesting Completion to be conducted and shall
furnish copies of the documents/proof evidencing fulfillment of the Completion conditions
and the proposed Completion Date.
 5.2
    
    The Transferor shall issue a letter in writing indicating its agreement to the
Completion within five (5) business days following receipt of the notice referred to in
Article 5.1, and furnish to the Transferor copies of the documents/proof evidencing
fulfillment of the Completion conditions as set forth in 2.(2) of Article 4 hereof.
 5.3
    
    The Transferee shall pay the consideration to the Transfer in full and in Renminbi
to the bank account designated by the Transfer in a lump sum.
 5.4
    
    As from the Completion Date, the Transferee shall obtain the associated non-equity
assets contained in the Target Assets and all the derivative interest arising therefrom
in accordance with the applicable P.R.C. laws; in the meantime, the Transferee shall also
obtain the associated equity contained in the Target Assets and all the derivative
interest arising therefrom in accordance with the applicable P.R.C. laws, and be entitled
to and assume the corresponding rights and obligations specified in the applicable laws,
regulations and the articles of association of the related companies.
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Article 6
    
    Title Alteration Procedures regarding the Target Assets
  Article 7
    
    Profits and Losses Incurred during the Transit Period
   Article 8
    
    Representations, Warranties and Covenants of the Transferor
 8.1
    
    The Transferor is an enterprise the title of which is vested with the whole people
and which was incorporated and validly subsisting under the P.R.C. laws. The Transferor
and its Affiliated Entities legally own the Target Assets and have not established,
directly or indirectly, any pledge, third party interest or other restrictions thereupon.
The Transferor has the right to transfer the Target Assets in accordance with this
Agreement.
 8.2
    
    The Transferor shall obtain approval and filing by the SASAC on the assets
valuation report submitted and complete the legal procedures on transfer of state-owned
property rights in accordance with The Interim Administrative Measures on the Transfer of
State-owned Property Rightsand the applicable laws and regulations on state-owned assets
management. In addition, the Transferor shall make all reasonable efforts to obtain from
the SASAC its approval on the Transfer of the Target Assets and waiver on the on-exchange
transactions thereof as soon as practical.
 8.3
    
    The execution and performance of this Agreement by the Transferor do not violate
any contracts or agreements which are legally binding upon it.
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8.4
    
    The execution and performance of this Agreement by the Transferor do not violate
any applicable laws or regulations, or the Transferors articles of association or other
constitutional documents.
 8.5
    
    The Transferor undertakes to actively cooperate actively, and procure its
Affiliated Entities to cooperate with the Transferee to complete any and all legal or
administrative procedures in connection with the Transfer hereunder, including without
limitation, amendments to the registration with the competent industrial and commercial
authorities and amendments to the title of the immovable property rights.
 8.6
    
    The Transferor hereby makes the following representations, warranties and covenants
in connection with the Target Entities as set out in Article 2.1 hereof:
       Article 9
    
    Representations, Warranties and Covenants of the Transferee
 9.1
    
    The Transferee is a company limited by shares duly organized, validly existing
and in good standing under the laws of the P.R.C.
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9.2
    
    The execution and performance of this Agreement by the Transferee do not violate
any contracts or agreements which are legally binding upon the Transferee.
 9.4
    
    The Transferee undertakes to consult with the Transferor on making appropriate
arrangements for the employees of the related entities involved in the Transfer of assets
contemplated hereunder.
 Article 10
    
    Taxation
  Article 11
    
    Event of Default
 11.1
    
    After this Agreement takes effect, if either party hereto fails to fulfill the
other obligations hereunder in accordance with the provisions hereunder, or any of its
representations or warranties is proved to be false, such party shall be deemed to be in
default. The defaulting party shall keep the non-defaulting party indemnified for any
and all losses the latter suffered as a result of the above defaults.
 11.2
    
    After this Agreement takes effect, if the Transferor fails to transfer the Target
Assets in accordance with the provisions hereunder, the Transferee shall have the right
to cancel this Agreement. In addition, the Transferor shall be liable for keeping the
Transferee indemnified for the expenses actually incurred and the losses suffered by the
Transferee as a result of the above failure of Transfer, including without limitation,
any and all related expenses incurred in connection with the Transferees taking delivery
of the Target Assets.
 11.3
    
    The parties hereto agree that, if the transaction contemplated hereunder fails as a
result of the failure to satisfy 2.(3) or 2.(4) of Article 4 hereof, neither of the
parties shall be liable for default of their respective obligations hereunder, and all
the expenses incurred by either party for the purpose of such transaction shall be for
their own account.
 Article 12
    
    Confidentiality
 Confidential Information
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Article 13
    
    Effectiveness, Amendments, Dissolution, Termination and Transfer of This Agreement
 13.1
    
    Effectiveness
  13.2
    
    Amendments and Dissolution
  13.3
    
    Termination
     13.4
    
    Transfer
  Article 14
    
    Notices
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Article 15
    
    Governing Law and Dispute Resolution
 15.1
    
    The execution, effectiveness, performance, interpretation and implementation as
well as any and all issues in connection with this Agreement shall be governed by the
laws of the P.R.C..
 15.2
    
    Any dispute arising from, out of or in connection with this Agreement shall be
settled through friendly consultations between the parties.
 Article 16
    
    Additional Provisions
 16.1
    
    Maintenance of Normal Operation and ManagementAs from the execution of this Agreement to the Completion Date, the parties hereto
agree to maintenance the normal operation and management of the Target Assets. The
Transferor guarantees that the Target Entities will not make any
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substantial adjustments to or dispose its own personnel issues and assets, nor will it
make any adjustments to or dispose the target non-equity assets or the related
personnel issues in violation of the purpose of this Agreement. In the event of any
material changes beyond the normal operational activities, the Transferor shall
forthwith notify the Transferee in writing of such changes.
 16.2
    
    Decision-making and Handover of Operation and ManagementUpon completion of the Completion of assets, the Transferee shall become a shareholder
of the Target Entities, being entitled to the due rights as a shareholder of the
company and assuming its obligations accordingly. The Transferee shall have the right
to recommend candidates of members of the board of directors and the supervisors
committee, and to participate in decision-making, operation and management of the
Target Entities. The Transferor shall do its utmost to provide any and all assistance
and handover the relevant materials and documents in its possession.
 16.3
    
    Disposal Plan regarding the Creditors rights and Debts.Upon completion of Transfer of the Target Assets, the creditors rights, debts and
contingent liabilities of the Target Entities shall continue to be assumed by such
Target Entities.
 16.4
    
    Statements, Confirmations and Undertakings.The statements, confirmations and undertakings given by the Transferor to the
Transferee in connection with the Transfer hereunder shall constitute an integral part
hereof and shall have the same legal effect with this Agreement.
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China National Petroleum Corporation
    PetroChina Company Limited
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