<PAGE>

                                                                    Exhibit 4.20


               LEASE CONTRACT FOR HOUSING UNIT OF CORPORATE SQUARE

                                                    Numbers: [2006] Guo Zu No. 3


PARTY A (the Lessor): China Galaxy Securities Company Limited
     Legal Representative: Zhu Li     Title: Chairman
     Address: Tower C, Corporate Square, 35 Financial Street, Xicheng District,
              Beijing
     Postal code: 100032
     Phone: (8610) 66568611
     Fax: (8610) 66568743

PARTY B (the Lessee): China Finance Online (Beijing) Co., Ltd.
     Legal Representative: Zhao Zhiwei     Title: Chief Executive Officer
     Address: Room 601, Ping'an Mansion, 23 Financial Street, Xicheng District,
              Beijing
     Postal code: 100032
     Phone: (8610) 66214728
     Fax: (8610) 33210423

     Pursuant to the Contracts Law and related laws and regulations of the
People's Republic of China, and for the purpose of defining their rights and
obligations, the Parties hereby agree on the contract as follows (the
"Contract") after friendly negotiations:


ARTICLE 1 QUALIFICATION, REPRESENTATIONS AND WARRANTIES

1.   Party A is a company duly established and existing under the laws of the
     People's Republic of China and the legal owner of Tower C of Corporate
     Square located at 35 Financial Street in Xicheng District in Beijing.
2.   Party B is a company duly established and existing under the law of the
     People's Republic of China and has the full qualification and power to sign
     and perform the Contract hereto.
3.   Party A and Party B both represent that they have completely understood and
     agreed on each provision of the Contract and are clearly aware of the
     benefits, risks and liabilities under the Contract.
4.   Party A and Party B both undertake to perform the Contract in a positive,
     careful and complete manner, following principles of fairness, justice and
     good faith and in compliance with requirements of relevant policies, laws
     and regulations.
<PAGE>

ARTICLE 2 SCOPE, AREA, TERM AND PURPOSE OF THE LEASE

1.   Per Party B's request, Party A agrees to lease to Party B the housing units
     of 946 to 949 of the ninth floor of Tower C of Corporate Square as
     indicated in Appendix 1 (the "Leased Units"), with a total area of 441
     square meters (referring to the construction area measured by the Bureau of
     Land Resources and Housing Management of Beijing Municipality) for a lease
     term of 60 months (the "Lease Term"), commencing on March 1, 2006 (the
     "Commencement Date") and ending on February 28, 2011.


ARTICLE 3 DELIVERY OF LEASED UNITS AND CONDITIONS FOR DELIVERY

1.   Party A shall deliver to Party B the Leased Units on the Commencement Date.
     Party A shall guarantee that the equipment for electricity, lighting, air
     conditioning, elevators and washing have been installed in the public areas
     of the Leased Units and are operating in good condition.
2.   Party A provides Party B with equipment and facilities in the Leased Units
     including but not limited to air conditioning, temperature controllers,
     alarms and fire sprinkler system, which shall be examined and confirmed by
     Party B's signature if no objection.


ARTICLE 4 DECORATION AND PLACEMENT

1.   In the case of decoration, placement and other changes to the Leased Units
     made by Party B, Party B shall give a prior notice to Party A and timely
     provide Party A or the Property Management Department of Corporate Square
     with various patterns, design plans, list of decoration materials and other
     documents with respect to decorating and placing internal equipment and
     auxiliary objects to facilitate the procedure for related approvals.
2.   Party B shall conduct the decoration after receipt of examination and
     approvals. Party B shall strictly perform in compliance with the approved
     decoration plan and relevant regulations set forth in Appendix 1 by the
     Property Management Department of Corporate Square. Party B shall pay the
     price of decoration and other related expenses.
3.   Party B shall undertake that decorations shall not have a negative impact
     either on the structure and framework of Corporate Square or on the
     interests of other lessees and users. Otherwise, Party B and not Party A
     shall exclusively bear all liabilities and losses arisen thereby.
4.   Party B shall undertake to be responsible for the equipment and facilities
     altered and improved in the decoration and to never violate related laws,
     regulations, rules or connected rules of Corporate Square listed in
     Appendix 1.


ARTICLE 5 FREE LEASE PERIOD, PREEMPTED RIGHT OF RENEWAL AND SUBLEASE
<PAGE>

1.   Party B has a right to a free lease period for 90 days from the
     Commencement Date. The term of free lease period is included in the whole
     Lease Term. Within the term of the free lease period, Party B shall have
     free rent, but it shall pay for fees other than the rent specified in
     accordance with the Contract.
2.   Upon the expiration of the Contract, Party B has a right to demand renewal
     of the lease, provided the conditions of Party B are the same as other
     parties have. Both parties shall negotiate and sign a new contract with
     respect to the rent and other fees during the renewal of the lease. Party B
     shall be deemed to waive the right of renewal in the event that Party B
     cannot notify Party A of the renewal request at least 3 months prior to the
     expiration of the Contract or both parties cannot reach a new contract at
     least 1 month prior to the expiration of the Contract.


ARTICLE 6 RENT, PROPERTY MANAGEMENT FEE, DEPOSIT AND PAYMENT

1.   The rent and property management fee are calculated in accordance with
     construction area measured by the Bureau of Land Resources and Housing
     Management of Beijing Municipality.
2.   The rent and property management fee shall be calculated in RMB and shall
     be collected monthly. The rent for each square meter per day is RMB4.62
     yuan and the property management fee for each square meter per day is
     RMB0.98 yuan.
3.   The property management fee shall be calculated on the basis of the
     property management fee charged by the Property Management Department in
     compliance with the rules of Corporate Square. Party A can adjust
     reasonably the property management fee pursuant to the conditions and
     procedures of Corporate Square.
4.   Within 3 working days after the execution of the Contract, Party B shall
     pay to Party A rent and property management fees for a 3 month period, in
     the total amount of RMB225351 yuan as the deposit, functioning as the
     security of Party B to make in time all payment of rent and property
     management fees to Party A.
5.   Within 3 working days after the execution of the Contract, Party B shall
     pay to Party A the property management fee of the first month in the amount
     of RMB13145.48 yuan. Party B shall pay RMB75117 yuan for the rent and
     property management fee of every month after term of the free lease period.
     Subsequent payment for the rent and property management fee of each month
     shall be made by Party B within the first 3 working days of such month. If
     the Commencement Date is not the initial date of a month, payment for the
     rent and property management fee of the month shall be calculated upon the
     actual days for lease.
6.   Party B shall remit the money for payment through bank transfer to the
     account designated by Party A as follows:

Account:
          RMB Account
          Bank: China Construction Bank, Beijing Fuxing Branch
          Account Number: 65100080350760014
          Foreign exchange shall be remitted to the account below:
          1.   Payee: China Galaxy Securities Company Limited
               Bank: China Merchants Bank, Beijing Finance Street Branch
<PAGE>

               Account: 6580115832001
          2.   Payee: China Galaxy Securities Company Limited

               Bank (HK$ account): Industrial and Commercial Bank of China,
                                   Beijing Branch
               Account: 0200000309200005493

7.   The rent of the contract includes land use premiums.


ARTICLE 7 RIGHTS AND OBLIGATIONS OF PARTY A

1.   Party A is entitled to the ownership and beneficial right of the Leased
     Units and any other property rights provided pursuant to the laws and
     regulations.
2.   During the Lease Term, Party A has a right to transfer the ownership of the
     Leased Units, in whole or part, to third parties regardless of consent from
     Party B. Party A shall transfer its rights and obligations under the
     Contract to such third parties. The rights and obligations of Party B under
     the Contract shall not be affected by the ownership transfer.
3.   During the Lease Term, Party A has a right to set up a mortgage, offer to
     compensate and exchange on the Leased Units, in whole or part, regardless
     of consent from Party B. The rights and obligations of Party B under the
     Contract shall not be affected by the Party A's activities as aforesaid.
4.   During the Lease Term, Party A shall pay the taxes imposed upon it by
     relevant laws and regulations.
5.   Party A has a right to dispatch its personnel to inspect the equipment and
     hardware of Corporate Square in the Leased Units, giving a prior notice to
     Party B except in emergency circumstances. Party A shall use its best
     endeavors to avoid any interruption to the ordinary working environment of
     Party B.


ARTICLE 8 RIGHTS AND OBLIGATIONS OF PARTY B

1.   Party B is entitled to use the Leased Units in accordance with the
     Contract.
2.   Party B shall carry out the business activities in the Leased Units in
     compliance with laws, regulations and rules of the People's Republic of
     China and is prohibited to harm Party A's reputation through its
     activities.
3.   Party B shall duly make the payments with respect to the rent, property
     management fee, electricity usage fee and any other charges it shall be
     responsible for.
4.   Starting from the Commencement Date, Party B shall purchase insurance for
     the properties in the Leased Units, including property insurance and third
     party liability insurance. Otherwise, Party B and not Party A shall be
     solely responsible for all liabilities and losses.
5.   Party B shall not alter the purpose of use of the Leased Units without
     consent in writing from Party A.
6.   Party B shall not re-lend, sublease, and exchange the Leased Units, in
     whole or part, to third parties or allow third parties to use the Leased
     Units by other means, without consent in writing from Party A.
<PAGE>

7.   Party B shall not alter the locking and security system on the gate of the
     Leased Units without consent in writing from Party A or approval from
     related departments.
8.   Party B shall not alter or move the equipment for usage of water and
     electricity and shall not enlarge the capacities of central air
     conditioning, without consent in writing from Party A.
9.   Party B shall take necessary actions to prevent the Leased Units from fires
     accident or man-made damage. Party B shall immediately notify to Party A
     with respect to any damage of the Leased Units. Party B shall restore the
     damaged parts of the Leased Units to their former condition within one
     month upon receipt of Party A's notice, provided that the damages resulted
     from negligence by Party B and its employees.


ARTICLE 9 LIABILITIES FOR BREACH

1.   The party in breach shall be responsible for the liabilities resulting from
     the breach. If both parties are deemed to be in breach of the Contract,
     liabilities shall be allocated between the two parties in accordance with
     corresponding facts and actual results of the breach.
2.   The party in breach shall pay liquidated damages to the other party duly
     performing the Contract. The other party is entitled to claim all of its
     losses incurred but with a limit to all actual losses.
3.   If Party A delays in delivering to Party B the Leased Units, it shall pay a
     late payment charge in the amount of 5/oo of the monthly rent for each day
     of delay.
4.   If Party B delays in making payment of fees, it shall pay a late payment
     charge in the amount of 5/oo of unpaid fees for each day of delay.
5.   If Party B delays in moving out of the Leased Units, it shall pay a late
     payment charge in amount of 1% of the monthly rent for each day of delay.
6.   If Party B in breach cannot duly pay the liquidated damages, late payment
     charge or indemnity due upon receipt of a notice from Party A asking for
     payment, Party B agrees that all the properties in the Leased Units can be
     taken by Party A as a lien and Party A has a right to dispose the
     properties in accordance with the laws.


ARTICLE 10 EXPIRATION AND TERMINATION OF THE CONTRACT

1.   The Contract shall be terminated automatically upon expiration of the Lease
     Term. Party A shall return the deposit of the rent and property management
     fee (less the amount ought to be paid by Party B and not including addition
     of interests or indemnity) to Party B within 30 days after Party B's
     completion of its performance.
2.   Party B shall complete the obligations below upon the expiration of the
     Lease Term or 7 days before the termination of the Contract:
     1)   Party B shall deliver to Party A the equipment and facilities in the
          Leased Units in good operating condition, except normal wear and tear,
          damages existing before the Lease Term or caused by force majeure
          events.
<PAGE>

     2)   Party B shall uninstall the decoration and equipment subsequently
          improved and restore the Leased Units to their former condition when
          moving out, except if given a written consent from Party A to maintain
          the decoration and improvement.
     3)   Party B shall pay off the rent, property management fee and
          electricity usage fee and other fees required.
3.   Party A has a right to unilaterally terminate the contract and keep the
     rent, provided that Party B has acted as follows. Party B shall be bound to
     pay the liquidated damages equal to 3 months' rent and other damages to any
     economic losses of Party A if:
     1)   Party B conducts illegal business activities.
     2)   Party B alters the purpose of use of the Leased Units without consent
          from Party A.
     3)   The Leased Units are used by third parties other than Party B without
          consent from Party A.
     4)   The Leased Units, in whole or part, are subleased, re-lent and
          exchanged to third parties or used in common by Party B and third
          parties, without consent from Party A.
     5)   Party B delays for more than 30 days in making payment for the rent,
          property management fee and other fees set forth in Article 6 of the
          Contract.
     6)   Party B is in a breach of Article 7 of the Contract and cannot
          efficiently redress within 30 days upon notice from Party A.
4.   Party B has a right to terminate the Contract before the expiration of the
     Lease Term because of the business development, after giving notice to
     Party A 3 months in advance and obtaining mutual consent.
5.   Party B has a right to terminate the contract and claim twice the amount of
     the deposit, provided that Party A cannot deliver the Leased Units within
     30 days from execution of the Contract and the receipt of the deposit from
     Party B.
6.   If Party A terminates the Contract for no reason, it shall pay to Party B
     twice the amount of the deposit and shall indemnify the direct losses
     suffered by Party B, such as decoration expenses.
7.   Upon the expiration of the Lease Term or 15 days after the termination of
     the Contract, any properties in the Leased Units that have not been moved
     out are regarded as being given up by Party B and Party B agrees to
     authorize Party A to dispose of these properties and charge Party B for any
     related costs.


ARTICLE 11 FORCE MAJEURE

1.   If one party cannot perform the Contract due to earthquake, typhoon, war,
     turbulence and other unexpected and inevitable factors, the party
     encountering the force majeure event shall immediately notify the other
     party and provide detailed information about the force majeure event and a
     certificate of non-performance, partial non-performance or
     delayed-performance. The certificate shall be issued by a local notary
     public from the place having the force majeure event. The party
     encountering the force majeure event shall not be held liable for
     indemnification.
<PAGE>

2.   If Party B cannot properly use the Leased Units due to the force majeure
     event, both parties shall negotiate to agree on subtraction of the rent and
     property management fee. If Party B cannot use the Leased Units at all due
     to the force majeure event, the payment for the rent and property
     management fee shall not be made until the Leased Units can be used in good
     condition. If the Leased Units cannot be used in good condition for 90
     days, Party B has a right to notify Party A of termination of the Contract.
     Party B shall reimburse the deposit and the rent paid in advance (less the
     actual usage fee and normal wear and tear) to Party B within 30 days upon
     receipt of a notice.


ARTICLE 12 GOVERNING LAW AND DISPUTE SETTLEMENT

1.   The Contract shall be governed by and construed in accordance with the laws
     of the People's Republic of China.
2.   Any dispute arising out of or relating to the Contract shall be resolved
     through friendly consultation between both parties. If the dispute is not
     resolved through consultation, any party has a right to submit to the China
     International Economic and Trade Arbitration ("CIETAC") for arbitration in
     accordance with the Arbitration Rules of CIETAC. The award of the
     arbitration tribunal shall be final and binding upon the two parties.


ARTICLE 13 MISCELLANEOUS

1.   Party B agrees that the Leased Units shall be managed by Party A (or the
     Property Management Company designated by Party A).
2.   The property management services shall include the cleaning of toilets,
     elevators, public corridors and maintenance of the equipment of Corporate
     Square, excluding the equipment improved by Party B inside the Leased
     Units.
3.   Party A and Party B both agree that they will conclude a separate contract
     with respect to the lease of underground parking spaces.


ARTICLE 14 ANNEX

1.   Any notice under the Contract shall be sent by means of fax, registered
     mail, courier or sent by specific individual to the legal addresses of the
     parties.
2.   If any provision of the Contract shall be held invalid, illegal or
     unenforceable, the validity and legality of the remaining provisions shall
     not be affected and shall not form a basis for both parties to refuse the
     performance of the Contract.
3.   Any matters not covered by the Contract may be negotiated and included in a
     supplementary contract entered into by both parties. Any supplementary
     contract and appendices shall be integrated into the Contract and have the
     same legal effect as that of the Contract.
4.   The Contract is made in three duplicates. Each party shall hold one and the
     Bureau of Land Resources and Housing Management of Beijing Municipality
     shall hold one for record. The three duplicates have the same legal effect.
<PAGE>

5.   The Contract comes into effect upon the signing by legal representatives or
     authorized representatives with chopped seals and comes to an end upon
     expiration of the Lease Term.



APPENDIX

1.   MAP OF LEASED UNITS







PARTY A: China Galaxy Securities Company Limited


/s/ [COMPANY SEAL]
By:  /s/ Zhu Li
     -----------------------------------------------------
     Legal Representative or authorized representative
Date: January 19, 2006



PARTY B: China Finance Online (Beijing) Co., Ltd.


By:  /s/ [COMPANY SEAL]
     ------------------------------------------------------
     Legal Representative or authorized representative
Date: January 19, 2006


Place of Execution:
3(rd) Floor, Corporate Square