Document:

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                                                                    Exhibit 4.12

                          [English translation of the Chinese language document]

                          CONTRACT FOR PURCHASE OF BUILDING

                         Contract No.: JDCX Zi 06-033-1

                                 March 23, 2006

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Contract No.: JDCX Zi 06-033-1

                        SCIENCE PARK OF ELECTRONICS CITY

    CONTRACT FOR TRANSFER WITH COMPENSATION OF ELECTRONICS STANDARD BUILDING

TRANSFEROR: BEIJING ELECTRONICS CITY CO., LTD. (HEREAFTER REFERRED TO AS "PARTY
A")

Registered address: A 12 Jiuxianqiao Road, Chaoyang District, Beijing (postal
code: 100016)

Legal representative: Yutong Bao

TRANSFEREE: TECHFAITH WIRELESS COMMUNICATION TECHNOLOGY (BEIJING) LIMITED
(HEREAFTER REFERRED TO AS "PARTY B")

Registered Address: 1 East Jiuxianqiao Road, Chaoyang District, Beijing

Legal representative: Jun Liu

In accordance with the "Contract Law of the People's Republic of China", the
"Law of the People's Republic of China on Urban Real Estate Administration" and
other related laws and regulations, on the basis of equality, voluntary and
consultations, the two parties have reached an agreement on the transfer with
compensation of the electronics standard building (Building D2 in IT Industry
Park) and entered into this contract for both parties to comply with.

ARTICLE 1 BASIS OF PROJECT CONSTRUCTION

1.1   Site of Project Construction: A 10 North Jiuxianqiao Road, Chaoyang
      District, Beijing

1.2   Approval Number of Project: JFG Zi (2004) No. 1831

1.3   Planning Permit Number: 2005 GJ Zi No. 0001

1.4   Land Use Permit: JZGY Zi (2005 Chu) No. 0639

ARTICLE 2 BASIC INFORMATION OF BUILDING

2.1   Address of Building: A 10 North Jiuxianqiao Road, Chaoyang District,
      Beijing

2.2   Location of Building: Floors 1, 2 and 3, Building D2, Section D, IT
      Industry Park, Electronics City at A 10 North Jiuxianqiao Road, Chaoyang
      District, Beijing

2.3   Building Area: 12,330 square meters

2.4   Building Structure: Reinforced Concrete Composite Structure

2.5   Other facts are based on actual condition of the building and the drawing.

<PAGE>

ARTICLE 3 AREA VERIFICATION

3.1   After signing this Contract and within 90 days of the building delivery,
      Party A shall entrust a qualified survey department to make survey to the
      building, and the actual area surveyed shall be verified and validated by
      both parties.

3.2   Transfer fee shall be calculated based on the area indicated on the Title
      Deed of the building.

ARTICLE 4 TRANSFER FEE AND PAYMENT METHOD

4.1   Transfer fee:

      Transfer fee is RMB3,700.00 per square meter of building area (including
      land grant fee). Total building transfer fee is RMB45,621,000.00 (based on
      the actual area indicated on the Title Deed).

4.2   Payment method: Payment shall be made in two installments.

      1)    Party B shall pay Party A the first installment of RMB 25,000,000.00
            prior to July 30, 2006.

      2)    Party B shall pay Party A the balance of RMB20,621,000.00 as second
            installment prior to January 10, 2007.

4.3   Taxes incurred from the transfer shall be paid by both parties
      respectively pursuant to the related national and municipal regulations of
      Beijing.

ARTICLE 5  BUILDING DELIVERY TERMS

5.1   Party A shall finish the procedure of four parties' examination and
      acceptance prior to July 30, 2006, and then deliver the building to Party
      B. Party B shall be responsible for verification and validation.

5.2   After Party B verifies and accepts the building, it can go through the
      delivery procedures and enter the building for renovation.

5.3   At the time of delivery, the municipal utilities (water, electricity and
      heat supply) and equipment that go with the building shall be at the
      normal condition.

5.4   Party A shall provide a copy of the "Beijing Municipality Construction
      Work Completion Registration" immediately after Party A obtains it.

ARTICLE 6 LIABILITIES FOR BREACH OF CONTRACT

6.1   In case Party A fails to deliver the building at the delivery time
      stipulated in the contract, it shall pay Party B 3/10,000 the transfer fee
      that Party B has paid to Party A, for each day during the period from the
      second day of the stipulated delivery date to the actual delivery date, as
      damages for breaching the Contract.

6.2   In case Party B fails to pay Party A the transfer fee on the date
      stipulated in the contract, it shall pay Party A 3/10,000 the amount
      overdue, for each day during the period from the second day of the
      stipulated paying date to the actual paying date, as damages for breaching
      the Contract. Payment overdue refers to the difference between the amount
      payable and the amount actually paid in a payment installment.

6.3   In case Party A fails to go through the property right transfer procedures
      on the

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      date stipulated in the Contract and does not hand over the Title Deed of
      the building to Party B on a timely basis, it shall pay Party B 3/10,000
      the total transfer fee, for each day during the period from the second day
      of the stipulated date to the actual delivery date of the Title Deed, as
      damages for breaching the Contract.

6.4   In case Party A breaches its representations or promises it made in this
      Contract or if there are flaws in the property right and land right that
      cause Party B unable to fulfill its related rights, Party B shall have
      right to terminate the contract and demand Party A to repay the deposit in
      double and pay Party B 3% the total transfer fee as damages for breaching
      the Contract.

ARTICLE 7 PROPERTY RIGHT REGISTRATION OF THE BUILDING

7.1   After Party B has paid all the fees payable, both parties shall go to a
      property right registration authority to go through the transfer deed
      procedures. Party A covenants to get the Title Deed ready within one year
      and hand it over to Party B (on condition that Party B has provided all
      the relevant materials and paid all the required fees).

7.2   The duration of the land use in connection with the building transferred
      to Party B is 50 years (based on the period indicated in the "state-owned
      land use permit").

7.3   While handling the property right registration and transfer deed, Party B
      shall provide supporting documents which are required to be provided by
      Party B in a timely manner.

7.4   Party A undertakes that the building and land use right under this
      Contract are not on lease or mortgage; Party A is responsible for all
      liabilities with respect to the building prior to the transfer date.

ARTICLE 8 WARRANTY OBLIGATIONS

8.1   With regard to the building and facilities that Party A has transferred to
      Party B, Party A shall be responsible for their warranty as per the
      related regulations of Beijing Municipality.

8.2   Party A shall fulfill its obligations for any quality problems within
      warranty during the warranty period; Party A shall not assume
      responsibilities for damages caused by force majeure or for reasons other
      than Party A's, but Party A may assist in repair and recovery while Party
      B shall bear the maintenance cost.

ARTICLE 9 AGREEMENT ON BUILDING USE

9.1   Party B may use the exterior walls of the building, but shall not set up
      facilities on the walls or change the overview of the building without
      Party A's permission.

9.2   The building is designed for industry, R&D or office use, and Party B
      shall not change the purpose of use of the building without Party A's
      consent.

9.3   During Party B's use of the building, Party B may not change the main
      structure of the premises, nor can it affect the building structure and
      the normal condition of other parts of the building.

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9.4   Party B shall not set up facilities outside the building and shall keep a
      clean and tidy environment.

9.5   In the use of the public facilities of the building, in case Party B
      causes damage to facilities or puts them out of order due to improper use
      or operations, Party B shall bear financial and legal liabilities.

ARTICLE 10 PROPERTY MANAGEMENT

10.1  Property management.

      Party A (or Party A's appointee) is responsible for property management.
      Party B and Party A shall enter into a separate property management
      contract. Party B agrees to pay its property management fee to Party A (or
      Party A's appointee) according to the property management contract (A
      property management contract shall be signed separately).

10.2  Power Fee.

      Party A (or Party A's appointee) is responsible for collecting fees for
      power (water, electricity and heat) used in connection with the building
      based on the standard set forth by the competent department of Beijing
      Municipality (indicated in the property management contract) and the
      standard is subject to change with the uniform fee change of Beijing
      Municipality. However, when there is a different agreement in the property
      management contract, then it shall be performed according to the property
      management contract.

10.3  Parking Spaces.

      The parking space within Building D2 is for use of Party B. Details will
      be included in the property management contract.

10.4  The cost for major repair, replacement and alteration of the public
      facilities, which is related to Party B's transferred building, shall be
      shared by relevant parties respectively according to their usage.

ARTICLE 11 FORCE MAJEURE

11.1  If the fulfillment of the obligations set forth by the Contract or its
      appendices is prevented due to unpredictable, unavoidable and
      uncontrollable events, neither party shall be held liable. However, the
      party affected by force majeure shall notify the other party in writing
      within 30 days of the occurrence of the force majeure and shall take
      active measures in finding out solutions.

11.2  Events of force majeure are defined according to national laws.

ARTICLE 12 SETTLING OF DISPUTES

12.1  All disputes arising from the performance of this Contract or related to
      the Contract shall be settled through friendly negotiation. If no
      settlement is reached through negotiation, the dispute shall then be
      submitted for arbitration to Beijing Arbitration Commission or be brought
      to the court.

12.2  In the course of negotiation or arbitration, the Contract and its
      appendices shall be executed continuingly, except for terms under dispute
      or other terms being hard to be implemented because of disputed terms.

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ARTICLE 13 OTHER TERMS AND CONDITIONS

13.1  The appendices of this Contract include:

            1) State-owned land use permit (photocopy);

            2) Counterpart of Party B's business license (photocopy);

            3) Project design drawing (Party A provides one package to Party B);

            4) Counterpart of Party A's business license (photocopy).

13.2  This Contract shall come into effect upon execution of both parties.
      Issues not covered by this contract shall be settled through negotiations
      between Party A and Party B and a supplemental agreement may be entered
      into.

13.3  The appendices of this Contract and supplemental agreements signed by both
      parties constitute an inseparable part of this Contract and shall have the
      same legal effect.

13.4  This Contract is made in five originals, both parties hold two copies and
      the other copy is for filing with Property Right Registration Department.

PARTY A:  BEIJING ELECTRONICS CITY CO., LTD.
/s/ [Special seal for contract]
Legal representative or his/her trustee:
Signature: /s/

Address: A 12 Jiuxianqiao Road, Chaoyang District, Beijing
Postal code: 100016
Phone: 64319258
Fax: 64360367
Bank: China Construction Bank, Electronics City Science Park Branch
Bank Account Number: 2610006889

PARTY B: TECHFAITH WIRELESS COMMUNICATION TECHNOLOGY (BEIJING) LIMITED
/s/ [Special seal for contract]

/s/ [Special seal for contract of Techfaith Intelligent Handset Technology
(Beijing) Limited]
Legal representative or his/her trustee:
Signature: /s/

Address: 1 East Jiuxianqiao Road, Chaoyang District, Beijing
Postal Code:
Phone:
Fax:
Bank: Xingye Bank, Beijing Guanganmen Branch
Bank Account Number: 321040101400014788

SIGNING DATE: MARCH 23, 2006<PAGE>

                                                                    Exhibit 4.13

                          [English translation of the Chinese language document]

                        CONTRACT FOR PURCHASE OF BUILDING

                         Contract No.: JDCX Zi 06-033-2

                                 March 23, 2006

<PAGE>

Contract No.: JDCX Zi 06-033-2

                        SCIENCE PARK OF ELECTRONICS CITY

    CONTRACT FOR TRANSFER WITH COMPENSATION OF ELECTRONICS STANDARD BUILDING

TRANSFEROR: BEIJING ELECTRONICS CITY CO., LTD. (HEREAFTER REFERRED TO AS "PARTY
A")

Registered address: A 12 Jiuxianqiao Road, Chaoyang District, Beijing (postal
code: 100016)
Legal representative: Yutong Bao

TRANSFEREE: TECHFAITH INTELLIGENT HANDSET TECHNOLOGY (BEIJING) LIMITED
(HEREAFTER REFERRED TO AS "PARTY B")

Registered Address: 1 East Jiuxianqiao Road, Chaoyang District, Beijing Legal
representative: Baozhuang Huo

In accordance with the "Contract Law of the People's Republic of China", the
"Law of the People's Republic of China on Urban Real Estate Administration" and
other related laws and regulations, on the basis of equality, voluntary and
consultations, the two parties have reached an agreement on the transfer with
compensation of the electronics standard building (Building D2 in IT Industry
Park) and entered into this contract for both parties to comply with.

ARTICLE 1 BASIS OF PROJECT CONSTRUCTION

1.1   Site of Project Construction: A 10 North Jiuxianqiao Road, Chaoyang
      District, Beijing

1.2   Approval Number of Project: JFG Zi (2004) No. 1831

1.3   Planning Permit Number: 2005 GJ Zi No. 0001

1.4   Land Use Permit: JZGY Zi (2005 Chu) No. 0639

ARTICLE 2 BASIC INFORMATION OF BUILDING

2.1   Address of Building: A 10 North Jiuxianqiao Road, Chaoyang District,
      Beijing

2.2   Location of Building: Floors 4, 5 and 6, Building D2, Section D, IT
      Industry Park, Electronics City at A 10 North Jiuxianqiao Road, Chaoyang
      District, Beijing

2.3   Building Area: 11,953 square meters

2.4   Building Structure: Reinforced Concrete Composite Structure

2.5   Other facts are based on actual condition of the building and the drawing

<PAGE>

ARTICLE 3 AREA VERIFICATION

3.1   After signing this Contract and within 90 days of the building delivery,
      Party A shall entrust a qualified survey department to make survey to the
      building, and the actual area surveyed shall be verified and validated by
      both parties.

3.2   Transfer fee shall be calculated based on the area indicated on the Title
      Deed of the building.

ARTICLE 4 TRANSFER FEE AND PAYMENT METHOD

4.1   Transfer fee:

      Transfer fee is RMB 3,700.00 per square meter of building area (including
      land grant fee). Total building transfer fee is RMB 44,226,100.00 (based
      on the actual area indicated on the Title Deed).

4.2   Payment method: Payment shall be made in two installments.

      1)    Party B shall pay Party A the first installment of RMB 25,000,000.00
            prior to July 30, 2006.

      2)    Party B shall pay Party A the balance of RMB 19,226,100.00 as second
            installment prior to January 10, 2007.

4.3   Taxes incurred from the transfer shall be paid by both parties
      respectively pursuant to the related national and municipal regulations of
      Beijing.

ARTICLE 5 BUILDING DELIVERY TERMS

5.1   Party A shall finish the procedure of four parties' examination and
      acceptance prior to July 30, 2006, and then deliver the building to Party
      B. Party B shall be responsible for verification and validation.

5.2   After Party B verifies and accepts the building, it can go through the
      delivery procedures and enter the building for renovation.

5.3   At the time of delivery, the municipal utilities (water, electricity and
      heat supply) and equipment that go with the building shall be at the
      normal condition.

5.4   Party A shall provide a copy of the "Beijing Municipality Construction
      Work Completion Registration" immediately after Party A obtains it.

ARTICLE 6 LIABILITIES FOR BREACH OF CONTRACT

6.1   In case Party A fails to deliver the building at the delivery time
      stipulated in the contract, it shall pay Party B 3/10,000 the transfer fee
      that Party B has paid to Party A, for each day during the period from the
      second day of the stipulated delivery date to the actual delivery date, as
      damages for breaching the Contract.

6.2   In case Party B fails to pay Party A the transfer fee on the date
      stipulated in the contract, it shall pay Party A 3/10,000 the amount
      overdue, for each day during the period from the second day of the
      stipulated paying date to the actual paying date, as damages for breaching
      the Contract. Payment overdue refers to the difference between the amount
      payable and the amount actually paid in a payment installment.

<PAGE>

6.3   In case Party A fails to go through the property right transfer procedures
      on the date stipulated in the Contract and does not hand over the Title
      Deed of the building to Party B on a timely basis, it shall pay Party B
      3/10,000 the total transfer fee, for each day during the period from the
      second day of the stipulated date to the actual delivery date of the Title
      Deed, as damages for breaching the Contract.

6.4   In case Party A breaches its representations or promises it made in this
      Contract or if there are flaws in the property right and land right that
      cause Party B unable to fulfill its related rights, Party B shall have
      right to terminate the contract and demand Party A to repay the deposit in
      double and pay Party B 3% the total transfer fee as damages for breaching
      the Contract.

ARTICLE 7 PROPERTY RIGHT REGISTRATION OF THE BUILDING

7.1   After Party B has paid all the fees payable, both parties shall go to a
      property right registration authority to go through the transfer deed
      procedures. Party A covenants to get the Title Deed ready within one year
      and hand it over to Party B (on condition that Party B has provided all
      the relevant materials and paid all the required fees).

7.2   The duration of the land use in connection with the building transferred
      to Party B is 50 years (based on the period indicated in the "state-owned
      land use permit").

7.3   While handling the property right registration and transfer deed, Party B
      shall provide supporting documents which are required to be provided by
      Party B in a timely manner.

7.4   Party A undertakes that the building and land use right under this
      Contract are not on lease or mortgage; Party A is responsible for all
      liabilities with respect to the building prior to the transfer date.

ARTICLE 8 WARRANTY OBLIGATIONS

8.1   With regard to the building and facilities that Party A has transferred to
      Party B, Party A shall be responsible for their warranty as per the
      related regulations of Beijing Municipality.

8.2   Party A shall fulfill its obligations for any quality problems within
      warranty during the warranty period; Party A shall not assume
      responsibilities for damages caused by force majeure or for reasons other
      than Party A's, but Party A may assist in repair and recovery while Party
      B shall bear the maintenance cost.

ARTICLE 9 AGREEMENT ON BUILDING USE

9.1   Party B may use the exterior walls of the building, but shall not set up
      facilities on the walls or change the overview of the building without
      Party A's permission.

9.2   The building is designed for industry, R&D or office use, and Party B
      shall not change the purpose of use of the building without Party A's
      consent.

9.3   During Party B's use of the building, Party B may not change the main
      structure of the premises, nor can it affect the building structure and
      the normal condition

<PAGE>

      of other parts of the building.

9.4   Party B shall not set up facilities outside the building and shall keep a
      clean and tidy environment.

9.5   In the use of the public facilities of the building, in case Party B
      causes damage to facilities or puts them out of order due to improper use
      or operations, Party B shall bear financial and legal liabilities.

ARTICLE 10 PROPERTY MANAGEMENT

10.1  Property management.

      Party A (or Party A's appointee) is responsible for property management.
      Party B and Party A shall enter into a separate property management
      contract. Party B agrees to pay its property management fee to Party A (or
      Party A's appointee) according to the property management contract (A
      property management contract shall be signed separately).

10.2  Power Fee.

      Party A (or Party A's appointee) is responsible for collecting fees for
      power (water, electricity and heat) used in connection with the building
      based on the standard set forth by the competent department of Beijing
      Municipality (indicated in the property management contract) and the
      standard is subject to change with the uniform fee change of Beijing
      Municipality. However, when there is a different agreement in the property
      management contract, then it shall be performed according to the property
      management contract.

10.3  Parking Spaces.

      The parking space within Building D2 is for use of Party B. Details will
      be included in the property management contract.

10.4  The cost for major repair, replacement and alteration of the public
      facilities, which is related to Party B's transferred building, shall be
      shared by relevant parties respectively according to their usage.

ARTICLE 11 FORCE MAJEURE

11.1  If the fulfillment of the obligations set forth by the Contract or its
      appendices is prevented due to unpredictable, unavoidable and
      uncontrollable events, neither party shall be held liable. However, the
      party affected by force majeure shall notify the other party in writing
      within 30 days of the occurrence of the force majeure and shall take
      active measures in finding out solutions.

11.2  Events of force majeure are defined according to national laws.

ARTICLE 12 SETTLING OF DISPUTES

12.1  All disputes arising from the performance of this Contract or related to
      the Contract shall be settled through friendly negotiation. If no
      settlement is reached through negotiation, the dispute shall then be
      submitted for arbitration to Beijing Arbitration Commission or be brought
      to the court.

12.2  In the course of negotiation or arbitration, the Contract and its
      appendices shall be executed continuingly, except for terms under dispute
      or other terms being

<PAGE>

      hard to be implemented because of disputed terms.

ARTICLE 13 OTHER TERMS AND CONDITIONS

13.1  The appendices of this Contract include:

            1) State-owned land use permit (photocopy);

            2) Counterpart of Party B's business license (photocopy);

            3) Project design drawing (Party A provides one package to Party B);

            4) Counterpart of Party A's business license (photocopy).

13.2  This Contract shall come into effect upon execution of both parties.
      Issues not covered by this contract shall be settled through negotiations
      between Party A and Party B and a supplemental agreement may be entered
      into.

13.3  The appendices of this Contract and supplemental agreements signed by both
      parties constitute an inseparable part of this Contract and shall have the
      same legal effect.

13.4  This Contract is made in five originals, both parties hold two copies and
      the other copy is for filing with Property Right Registration Department.

PARTY A:  BEIJING ELECTRONICS CITY CO., LTD.
/s/ [special seal for contract]
Legal representative or his/her trustee:
Signature: /s/

Address: A 12 Jiuxianqiao Road, Chaoyang District, Beijing
Postal code: 100016
Phone: 64319258
Fax: 64360367
Bank: China Construction Bank, Electronics City Science Park Branch
Bank Account Number: 2610006889

PARTY B: TECHFAITH INTELLIGENT HANDSET TECHNOLOGY (BEIJING) LIMITED
/s/ [special seal for contract]
Legal representative or his/her trustee:
Signature: /s/

Address: 1 East Jiuxianqiao Road, Chaoyang District, Beijing
Postal Code:
Phone:
Fax:
Bank: Xingye Bank, Beijing Guanganmen Branch
Bank Account Number: 321040100100052548

SIGNING DATE: MARCH 23, 2006

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