79




                                  EXHIBIT 10.2
                                  ------------



           This is an Exhibit to the Form 20-F of Sinovac Biotech Ltd.
           -----------------------------------------------------------


                     Attached find the following materials:


    Share Purchase Agreement entered into between Net Force Systems Inc. and
    ------------------------------------------------------------------------
                       Lily Wang, dated September 24, 2003
                       -----------------------------------


                               End of Exhibit 10.2

                                    ---------






                                       80




                            SHARE PURCHASE AGREEMENT
                            ------------------------

     THIS SHARE PURCHASE  AGREEMENT  (together with all schedules,  exhibits and
     ------------------------------
all ancillary agreements contemplated herein are hereinafter referred to as this
"Agreement"),  is entered  into as of the 24th day of  September,  2003,  by and
between Net Force Systems Inc., a  corporation  organized  under the laws of the
Country of Antigua (the "Net Force") and Lily Wang ("Wang"),  a natural  person.
Net Force and the Wang are referred to collectively as the "Parties".

     WHEREAS,  Wang owns not less than 51% ownership interest in Sinovac Biotech
     -------
Co, Ltd ("Sinovac"), a company organized under the laws of the People's Republic
of China ("PRC");

     WHEREAS,  Wang  desires to sell and Net Force  desires to acquire  the Wang
     -------
Shares  equalling  68,136,000  shares  representing  not less than 51% ownership
interest  in Sinovac in  consideration  for  10,000,000  newly-issued  shares of
common stock of Net Force,  at a stated  value of $0.60 per share,  constituting
approximately 37% of Net Force's  outstanding  capital stock after such issuance
on a fully-diluted basis, on the terms and conditions hereinafter provided;

     NOW THEREFORE,  on the stated premises and for and in  consideration of the
     -------------
mutual covenants and agreements hereinafter set forth and the mutual benefits to
the Parties to be derived herefrom, it is hereby agreed as follows:

                                    ARTICLE I
                                    ---------
                         REPRESENTATIONS AND WARRANTIES
                         ------------------------------
                           OF THE SINOVAC SHAREHOLDER
                           --------------------------

The Sinovac Shareholder represents and warrants as follows:

     Section 1.01 - Organization of Sinovac. Sinovac is a company duly organized
                    -----------------------
and validly  existing  under the laws of PRC and has the corporate  power and is
duly authorized, qualified, and licensed under all applicable laws, regulations,
ordinances,  and orders of public  authorities  to  undertake  the  transactions
contemplated by this Agreement, to own all of its properties and assets to carry
on its business.  The execution and delivery of this Agreement does not, and the
consummation  of the  transactions  contemplated  hereby  will not,  violate any
provision  of  Sinovac's  articles  of  incorporation  or bylaws (or the foreign
equivalent thereof).  Sinovac has taken, or will have taken prior to Closing (as
described in Article III herein),  all actions  required by law, its articles of
incorporation,  or  otherwise,  to authorize  the execution and delivery of this
Agreement.  Sinovac has, or will have prior to Closing (as  described in Article
III herein), full power, authority,  and legal right and has, or will have prior
to Closing (as  described in Article III herein),  taken all action  required by
law, its bylaws,  articles of incorporation (or the foreign equivalent  thereof)
and otherwise to consummate the transactions herein contemplated.

     Section  1.02 -  Capitalization  and  Outstanding  Shares.  The  authorized
                      ----------------------------------------
capitalization  of Sinovac  consists of  250,000,000  authorized  common shares,
$0.001 par value per share,  of which  133,600,000 are issued and outstanding as
of August 31, 2003. All outstanding  share of Sinovac are validly issued,  fully
paid, and  non-assessable and not issued in violation of the preemptive or other
rights of any person.

     Section 1.03 - Options or Warrants or Subscriptions.  There are no existing
                    ------------------------------------
options, warrants, calls, subscriptions or commitments of any character relating
to any authorized and unissued stock of any class of Sinovac.

     Section 1.04 - Ownership of Sinovac  Shares.  With respect to herself,  the
                    ----------------------------
Sinovac  Shareholder is the legal and beneficial owner of that number of Sinovac
shares set forth  opposite her name in the attached  Schedule A (which  together






                                       81




constitute 51% of all of Sinovac's  outstanding  shares),  free and clear of any
claims,  charges,   equities,   liens,  security  interests,   and  encumbrances
whatsoever.

     Section 1.05 - Shares  Validly  Issued.  With respect to the Sinovac Shares
                    -----------------------
issued to her the Sinovac Shares have been validly issued to the Shareholder and
are fully paid, fully vested,  non-assessable and not issued in violation of the
pre-emptive or other rights of any person.

     Section  1.06 - Valid  Transfer of Fully  Vested  Shares.  With  respect to
                     ----------------------------------------
herself,  the  Sinovac  Shareholder  has full right,  power,  and  authority  to
transfer,  assign,  convey,  and  deliver its Sinovac  Shares.  With  respect to
herself,  delivery by the Sinovac  Shareholder of such shares at the Closing (as
described  in Article III herein)  will convey to Net Force good and  marketable
title to such Sinovac Shares, free and clear of any claims,  charges,  equities,
liens, security interests, and encumbrances whatsoever.

     Section 1.07 - Underlying Transaction Lawful. All transactions contemplated
                    -----------------------------
by this  Agreement are lawful under the laws of Antigua and are  enforceable  in
the courts of Antigua. This Agreement and each of its terms are lawful under the
laws of Antigua and are enforceable in Antigua courts.

     Section 1.08 - Enforceable  Obligation.  The  transactions  contemplated by
                    -----------------------
this  Agreement  are the  valid  and  binding  obligations  of the  Shareholder,
enforceable against the respective Shareholder,  by Net Force in accordance with
the terms of this Agreement.

     Section 1.9 - No  Conflicts.  The  execution  and  delivery by each Sinovac
                   -------------
Shareholder of this Agreement,  the  performance by each Sinovac  Shareholder of
his, her or its  obligations  under this Agreement and the  consummation  of the
transactions  contemplated  hereby do not and will  not:  (i)  conflict  with or
result in a violation or breach of, (ii)  constitute  (with or without notice or
lapse of time or both) a default under, (iii) require any Sinovac Shareholder to
obtain any  consent,  approval  or action of,  make any filing  with or give any
notice to any person as a result or under the terms of,  (iv)  result in or give
to  any  person  any  right  of  termination,   cancellation,   acceleration  or
modification  in or with  respect  to,  (v)  result in or give to any person any
additional  rights or  entitlement  to  increased,  additional,  accelerated  or
guaranteed  payments  under, or (vi) result in the creation or imposition of any
lien  upon  any  Sinovac  Shareholder  or any of  their  respective  assets  and
properties under any contract to which any Sinovac Shareholders is bound.

     Section  1.10 - Voting  Trusts.  The Sinovac  Shares are not subject to any
                     --------------
voting trust  agreement or other contract  restricting or otherwise  relating to
the voting or disposition of the Sinovac Shares.

     Section  1.11 -  Governmental  Authorizations  and  Licenses.  The  Sinovac
                      -------------------------------------------
Shareholder has, or will have upon Closing (as described in Article III herein),
all licenses,  franchises,  permits, and other governmental  authorizations that
are  legally  required  to enable it to conduct  its  business  in all  material
respects as conducted.  No  authorization,  approval,  consent,  or order of, or
registration,  declaration, or filing with, any court or other governmental body
is  required  in  connection  with the  execution  and  delivery  by the Sinovac
Shareholders of this Agreement and  consummation by the Sinovac  Shareholders of
the transaction contemplated hereby.

     Section  1.12  -  Compliance  with  Laws  and   Regulations.   The  Sinovac
                       -----------------------------------------
Shareholder  has complied with all  applicable  statutes and  regulations of any
applicable laws except to the extent that noncompliance  would not result in the
occurrence of any material liability for any Sinovac Shareholder.

     Section 1.13 - Power of Stock  Transfer.  The Sinovac  Shareholder has duly
                    ------------------------
executed a stock transfer power in the substantial form as set forth in Schedule
B.






                                       82




                                   ARTICLE II
                                   ----------
                         REPRESENTATIONS, COVENANTS AND
                         ------------------------------
                             WARRANTIES OF NET FORCE
                             -----------------------

Net Force represents and warrants as follows:

     Section  2.01  -  Organization  and  Due  Authorization.  Net  Force  is  a
                       -------------------------------------
corporation  duly organized,  validly  existing,  and in good standing under the
laws  of the  Country  of  Antigua  and  has  the  corporate  power  and is duly
authorized,  qualified,  and licensed  under all applicable  laws,  regulations,
ordinances,  and orders of public  authorities  to own all of its properties and
assets.  The  execution  and  delivery  of  this  Agreement  does  not,  and the
consummation  of the  transactions  contemplated  hereby  will not  violate  any
provision  of Net Force's  articles of  incorporation  or bylaws.  Net Force has
taken all action  required by law and under its articles of  incorporation,  its
bylaws,  or otherwise to authorize the execution and delivery of this Agreement,
and Net  Force has full  power,  authority,  and  legal  right and has taken all
action required by law, its articles of  incorporation,  bylaws, or otherwise to
consummate the transactions herein contemplated.

     Section  2.02  -  Capitalization   and  Outstanding   Shares.  Net  Force's
                       ------------------------------------------
authorized  capitalization  currently  consists of 100,000,000  shares of common
stock,  par value $.001, of which  17,066,033  shares of common stock are issued
and  outstanding as of the date hereof and 50,000,000  shares of preferred stock
of which no  shares  are  outstanding  as of the date  hereof.  All  issued  and
outstanding shares are legally issued, fully paid, non-assessable and not issued
in violation of the pre-emptive or other rights of any person.

     Section 2.03 - Options or Warrants or Subscriptions.  There are no existing
                    ------------------------------------
options, warrants, calls, subscriptions or commitments of any character relating
to the authorized and unissued stock of Net Force.

     Section 2.04 - Approval of  Agreement.  The board of directors of Net Force
                    ----------------------
has approved this Agreement and the transactions contemplated hereby.

     Section 2.05 - Underlying Transaction Lawful. All transactions contemplated
                    -----------------------------
by this  Agreement  are lawful  under the laws of the Country of Antigua and are
enforceable  in the courts of Antigua.  This Agreement and each of its terms are
lawful under the laws of the Country of Antigua and are  enforceable  in Antigua
courts.

     Section 2.06 - Enforceable Obligation. The transaction contemplated by this
                    ----------------------
Agreement is a valid and binding  obligation of Net Force,  enforceable  against
it, by the other Parties in accordance with the terms of this Agreement.

     Section 2.07 - Compliance with Laws and Regulations. Net Force has complied
                    ------------------------------------
with all applicable  statutes and  regulations of any applicable  laws except to
the extent that noncompliance would not result in the occurrence of any material
liability for Net Force.

     Section  2.08  - No  Information  Statement  on  14C  Required.  Net  Force
                      ---------------------------------------------
represents  and warrants to the Sinovac  Shareholders  that under to the laws of
the Country of Antigua, Net Force is not legally required to file an information
statement  on  Schedule  14C  promulgated  under the  Exchange  Act of 1934,  as
amended.

                                   ARTICLE III
                                   -----------
                 PLAN OF PURCHASE AND SALE OF THE SINOVAC SHARES
                 -----------------------------------------------

     Section 3.01 - The Purchase and Sale of the Sinovac Shares.
                    -------------------------------------------

     (a)  Wang agrees to assign,  transfer,  and deliver to Net Force,  free and
clear of all liens, pledges, encumbrances, charges, restrictions or known claims







                                       83




of any kind,  nature, or description,  68,136,000 shares of the capital stock of
Sinovac, constituting 51% of the issued and outstanding capital stock of Sinovac
as of September 24, 2003.

     (b)  Net  Force  agrees  to  issue  and  deliver  to  the  Wang  10,000,000
newly-issued  shares of Net  Force's  common  stock,  par value $.001 and stated
value of $0.60 per share,  to Wang.  The shares  issued by Net Force  under this
Section  3.01(b)  shall be issued with the rights of  registration  contained in
that  certain  registration  rights  agreement  between  the Wang and Net  Force
attached hereto as Schedule D.

     Section  3.02 -  Closing.  The  closing  ("Closing")  of  the  transactions
                      -------
contemplated  by this Agreement shall occur after the signing of this Agreement,
after the  fulfillment  of all  conditions  precedent  set forth in Article  III
hereof and at such time and place as the parties may  mutually  agree  ("Closing
Date").

     Section  3.03 - Closing  Events.  At the  Closing,  each of the  respective
                     ---------------
Parties  hereto shall execute,  acknowledge,  and deliver (or shall ensure to be
executed, acknowledged, and delivered), as applicable, the following:

     (a)  In the case of the Wang: (i) a completed  Schedule A containing a list
indicating  the  number of shares  owned by her,  and the number of shares to be
transferred  by her  under  this  Agreement;  (ii) a stock  transfer  power  and
authorization  of  designee  executed  by  Wang  listed  on  Schedule  B in  the
substantial   form  set  forth  in  Schedule  A;  and  (iii)  a  certificate  of
registration  issued by the office of  registration  of the PRC  evidencing  the
approximate 51% ownership interest of Sinovac by Wang;

     (b)  In the case of Net Force;  (i) an opinion  of counsel as  required  by
Section  2.07 of this  Agreement;  and (ii) to Wang set forth on Schedule E that
number of newly issued Net Force Shares set forth beside Wang's name on Schedule
E.

                                   ARTICLE IV
                                   ----------
       SPECIAL REPRESENTATIONS AND COVENANTS WITH RESPECT TO COMMON SHARES
       -------------------------------------------------------------------
                    ISSUED BY THE COMPANY TO THE SHAREHOLDERS
                    -----------------------------------------

     Section  4.01 - Shares  Issued  by Net  Force to Wang Not  Registered.  The
                     -----------------------------------------------------
consummation  of  this  Agreement  and  the  transactions  herein  contemplated,
including  the  issuance  of common  shares by Net Force to Wang as set forth in
Article III,  constitute  the offer and sale of securities  under the Securities
Act of 1933, as amended (the  "Securities  Act") and applicable  state statutes.
Wang  acknowledge  that the shares of Net Force to be delivered to Wang pursuant
to this Agreement have not been registered  under the Securities Act or the laws
of  any  other  jurisdiction,   and  that  therefore  the  stock  is  not  fully
transferable except as permitted under various exemptions,  if any, contained in
the  Securities  Act and the rules of the  Securities  and  Exchange  Commission
interpreting  the Securities  Act. Under US law, Net Force's common stock cannot
be sold or transferred  by Wang unless they are  subsequently  registered  under
applicable law or an exemption from  registration  is available.  The provisions
contained  in  this  paragraph  are  intended  to  ensure  compliance  with  the
Securities Act.

     Section 4.02 - Regulation S  Representations.  For purposes of this Section
                    -----------------------------
4.02,   "United  States"  includes  the  United  States,   its  territories  and
possessions,  any state, and the District of Columbia. Each Shareholder is not a
"U.S.  Person",  defined in Rule 902(k) of the  Securities Act as any one of the
following:  (i) any  natural  person  resident  in the United  States;  (ii) any
partnership or corporation  organized under the laws of the United States; (iii)
any estate of which any executor or  administrator  is a U.S.  person;  (iv) any
trust of which  any  trustee  is a U.S.  person;  (v) any  agency or branch of a
foreign entity located in the United States; (vi) any non-discretionary  account
or similar  account  (other  than an estate or trust)  held by a dealer or other
fiduciary  for  the  benefit  or  the  account  of  a  U.S.  person;  (vii)  any
discretionary account or similar account (other than an estate or trust) held by
a dealer  or  other  fiduciary  organized,  incorporated  or (if an  individual)
resident in the United States;  (viii) any partnership or  corporation,  if such







                                       84




entity  was formed  under the laws of a foreign  jurisdiction  by a U.S.  person
principally for the purpose of investing in securities not registered  under the
Securities Act, unless it is organized or incorporated, and owned, by accredited
investors.  Each Shareholder did not receive offering  materials with respect to
the transactions  contemplated by the Agreement.  At the time of this Agreement,
each  Shareholder is outside of the United States.  Therefore Wang agrees not to
sell or  otherwise  dispose  of any of the common  shares of Net Force  received
pursuant to this agreement unless such Shareholder:

     (a)  has  delivered  to Net  Force a  written  legal  opinion  in form  and
          substance satisfactory to counsel for Net Force to the effect that the
          disposition is  permissible  under the terms of the Securities Act and
          the rules and regulations promulgated thereunder;

     (b)  has complied with the registration and prospectus  requirements of the
          Securities Act relating to such disposition; or

     (c)  has presented Net Force satisfactory  evidence that such a disposition
          is exempt from  registration  under the Securities  Act. The Net Force
          shall place a stop transfer  order  against  transfers of shares until
          one of the  conditions  set  forth in this  paragraph  have  been met.
          Furthermore,  Wang agrees that the certificates  evidencing the common
          shares that each will receive  under this  Agreement  will contain the
          following legend or one substantially similar:

(begin boldface)
THE SECURITIES  REPRESENTED  HEREBY HAVE NOT BEEN  REGISTERED  UNDER THE FEDERAL
SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR REGISTERED OR QUALIFIED UNDER
THE  SECURITIES  LAWS OF ANY STATE AND MAY NOT BE SOLD,  TRANSFERRED,  ASSIGNED,
PLEDGED OR HYPOTHECATED (1) ABSENT AN EFFECTIVE  REGISTRATION  THEREOF UNDER THE
ACT;  OR  (2)  ABSENT  AN  OPINION  OF  COUNSEL,  WHICH  OPINION  IS  REASONABLY
SATISFACTORY IN FORM AND SUBSTANCE TO THE COMPANY AND ITS COUNSEL, TO THE EFFECT
THAT SUCH  REGISTRATION  IS NOT  REQUIRED  UNDER SAID ACT OR SUCH STATES OR THAT
SUCH  TRANSACTION  COMPLIES WITH THE RULES  PROMULGATED  BY THE  SECURITIES  AND
EXCHANGE COMMISSION UNDER SAID ACT OR SUCH STATES.
(end boldface)

     Section 4.03 - Third Party Consents and Certificates.  The Parties agree to
                    -------------------------------------
cooperate  with each other in order to obtain any required  third party consents
to this Agreement and the transactions herein and therein contemplated.

     Section 4.04 - Indemnification.
                    ---------------

     (a) Wang hereby agrees to indemnify  Net Force,  its  respective  officers,
agents and directors as of the date of execution of this  Agreement  against any
loss,  liability,  claim, damage or expense (including,  but not limited to, any
and all expenses whatsoever reasonably incurred in investigating,  preparing, or
defending  against  any  litigation,  commenced  or  threatened,  or  any  claim
whatsoever),  to which it or they may become subject  arising out of or based on
any inaccuracy appearing in or  misrepresentations  made under Article I of this
Agreement.  The indemnification provided for in this paragraph shall survive the
Closing and consummation of the transactions contemplated hereby and termination
of this Agreement.

     (b) Net Force hereby  agrees to indemnify  Wang as of the date of execution
of this  Agreement  against  any  loss,  liability,  claim,  damage  or  expense
(including,  but not  limited  to, any and all  expenses  whatsoever  reasonably
incurred in  investigating,  preparing,  or  defending  against any  litigation,
commenced  or  threatened,  or any claim  whatsoever),  to which they may become
subject   arising  out  of  or  based  on  any   inaccuracy   appearing   in  or
misrepresentations made under Article II of this Agreement.  The indemnification
provided for in this paragraph shall survive the Closing and consummation of the
transactions contemplated hereby and termination of this Agreement.







                                       85




                                    ARTICLE V
                                    ---------
                CONDITIONS PRECEDENT TO OBLIGATIONS OF NET FORCE
                ------------------------------------------------

     The  obligations  of Net Force  under  this  Agreement  are  subject to the
satisfaction, at or before the Closing Date, of the following conditions:

     Section  5.01  -  Accuracy  of  Representations.  The  representations  and
                       -----------------------------
warranties  made by Wang in this Agreement were true when made and shall be true
at the  Closing  Date with the same force and effect as if such  representations
and  warranties  were made at and as of the  Closing  Date  (except  for changes
therein permitted by this Agreement),  and Wang shall have performed or complied
with all pre-closing  covenants and conditions  required by this Agreement to be
performed or complied with by them prior to or at the Closing.

     Section 5.02 - No Material Adverse Change. Prior to the Closing Date, there
                    --------------------------
shall not have occurred any material adverse change in the financial  condition,
business, or operations of Sinovac nor shall any event have occurred which, with
the lapse of time or the  giving of  notice,  may cause or create  any  material
adverse change in the financial condition, business or operations of Sinovac.

     Section 5.03 - Deliverables.  Each deliverable  required to be delivered by
                    ------------
Wang under Article I and/or Section 3.01 of this Agreement has been delivered.


                                   ARTICLE VI
                                   ----------
                                  MISCELLANEOUS
                                  -------------

     Section  6.01 -  Governing  Law.  This  Agreement  shall  be  governed  by,
                      --------------
enforced,  and construed  under and in accordance with the laws of the County of
Antigua.

     Section 6.02 - Resolution of Disputes.
                    ----------------------

          (a)  Any dispute,  controversy  or claim arising out of or relating to
               this Agreement,  or the  interpretation,  breach,  termination or
               validity  hereof,   shall  first  be  resolved  through  friendly
               consultation,   if  possible.   Such  consultation   shall  begin
               immediately  after one party has  delivered  to the other party a
               written request for such consultation (the "Consultation  Date").
               If the dispute  cannot be resolved  within 30 days  following the
               Consultation  Date, the dispute shall be submitted to arbitration
               upon the  request of either  party,  with  written  notice to the
               other party.

          (b)  Arbitration.  The arbitration shall be conducted in New York, New
               -----------
               York under the auspices of the American  Arbitration  Association
               ("AAA") in accordance with the commercial  arbitration  rules and
               supplementary procedures for international commercial arbitration
               of the AAA.  There  shall be  three  arbitrators--one  arbitrator
               shall be  chosen  by each  party to the  dispute  and  those  two
               arbitrators  shall choose the third  arbitrator.  All arbitration
               proceedings  shall be  conducted  in  English.  Each party  shall
               cooperate  with  the  other  in  making  full  disclosure  of and
               providing  complete  access  to  all  information  and  documents
               requested by the other party in connection  with the  arbitration
               proceedings.  Arbitration shall be the sole,  binding,  exclusive
               and final remedy for resolving  any dispute  between the parties;







                                       86




               either party may apply to any court of competent  jurisdiction in
               the State of New York for enforcement of any award granted by the
               arbitrators.

          (c)  During the period  when a dispute is being  resolved,  except for
               the  matter  being  disputed,  the  parties  shall  in all  other
               respects continue to abide by the terms of this Agreement.

     Section  6.03 - Notices.  Any notice or other  communications  required  or
                     -------
permitted hereunder shall be sufficiently given if personally delivered to it or
sent by  registered  mail or  certified  mail,  postage  prepaid,  or by prepaid
telegram addressed as follows:

     (a)  If to Net Force, address as follows:

          Net Force Systems Inc.
          C/O Stepp Law Group
          1301 Dove Street, Suite 460
          Newport Beach, California
          92660
          Telephone:  949-660-9700
          Fax: 949-660-9010
          Attn: Thomas E. Stepp, Jr.

     (b)  If to Wang, address as follows:

          Lily Wang
          Suite 202 - 300 Murchison Drive
          Millbrae, CA 94030
          USA
          Telephone: 650-259-9688
          Fax:

or such other  addresses  as shall be  furnished  in writing by any party in the
manner for giving notices hereunder,  and any such notice or communication shall
be deemed to have been given as of the date so delivered, mailed or telegraphed.

     Section 6.04 - Attorney's  Fees. In the event that any party institutes any
                    ----------------
action or suit to enforce this  Agreement  or to secure  relief from any default
hereunder or breach hereof,  the breaching  party or parties shall reimburse the
non-breaching party or parties for all costs,  including  reasonable  attorney's
fees,  incurred in  connection  therewith  and in  enforcing or  collecting  any
judgment rendered therein.

     Section  6.05 -  Schedules  Knowledge.  Each party is presumed to have full
                      --------------------
knowledge of all information set forth in the other party's schedules  delivered
pursuant to this Agreement.

     Section  6.06 - Entire  Agreement.  This  Agreement  represents  the entire
                     -----------------
agreement between the parties relating to the subject matter thereof.

     Section 6.07 - Survival Termination.  The representations,  warranties, and
                    --------------------
covenants  of the  respective  parties  shall  survive the Closing  Date and the
consummation  of the  transactions  herein  contemplated  for a period  of three
months.  All rights and obligations under this entire Agreement shall be binding
upon and  inure to the  benefit  of the  heirs,  executors,  administrators  and
assigns of the parties.








                                       87




     Section 6.08 -  Counterparts.  This  Agreement  may be executed in multiple
                     ------------
counterparts,  each of which shall be deemed an original  and all of which taken
together  shall be but a single  instrument.  For  purposes  of this  Agreement,
facsimile signatures may be deemed originals.

     Section 6.09 - Amendment or Waiver.  Every right and remedy provided herein
                    -------------------
shall be cumulative with every other right and remedy, whether conferred herein,
at law, or in equity, and may be enforced concurrently  herewith,  and no waiver
by any  party  of the  performance  of any  obligation  by the  other  shall  be
construed as a waiver of the same of any other  default  then,  theretofore,  or
thereafter  occurring or existing.  At any time prior to the Closing Date,  this
Agreement may be amended by a writing signed by all parties hereto, with respect
to any of the  terms  contained  herein,  and  any  term  or  condition  of this
Agreement may be waived or the time for performance may be extended by a writing
signed by the party or parties for whose benefit the provision is intended.

              [The remainder of this page intentionally left blank]
              -----------------------------------------------------





                                       88




SIGNATURES
- ----------

IN WITNESS WHEREOF the parties hereto have duly executed this Agreement.
- ------------------------------------------------------------------------



                                                     NET FORCE SYSTEMS INC.
                                                     ----------------------


                                                     Per:  /s/ He Ping Wang
- ----------------------------                               ---------------------
(Witness/Seal)                                       He Ping Wang
                                                     Director

                                                     Per:  /s/ Lily Wang
- ----------------------------                               ---------------------
(Witness/Seal)                                       Lily Wang
                                                     Director

                                                     Per:  /s/ Wei Dong Yin
- ----------------------------                               ---------------------
(Witness/Seal)                                       Wei Dong Yin
                                                     Director



                                                     LILY WANG
                                                     ---------


                                                      /s/ Lily Wang
- ----------------------------                         ---------------------------
(Witness/Seal)                                       Lily Wang






                                       89




                                   SCHEDULE A
                                   ----------

                               SINOVAC SHAREHOLDER
                               -------------------




Name and Address                 Number of Shares Owned  Number of Shares to Be Transferred
- ----------------                 ----------------------  ----------------------------------

                                                                
Lily Wang                             68,136,000                      68,136,000
Suite 202 - 300 Murchison Drive
Millbrae, CA 94030
USA







                                       90




                                   SCHEDULE B
                                   ----------

                     SHAREHOLDERS' STOCK TRANSFER POWER AND
                     --------------------------------------
                            AUTHORIZATION OF DESIGNEE
                            -------------------------



     FOR VALUE RECEIVED,  the undersigned  ("Assignor") hereby sells,  transfers

and assigns unto Net Force Systems Inc.  ("Assignee"),  a corporation  organized

under the laws of the Country of Antigua,  68,136,000 shares of the common stock

representing  not less than 51% of Sinovac,  a corporation  organized  under the

laws of the PRC and does hereby  irrevocably  constitute and appoint each of Net

Force's  officers  and  directors as its  attorney-in-fact  to transfer the said

shares on the books and records of Net Force, with full power of substitution in

the  premises.  This  Stock  Transfer  Power  shall be  subject to the terms and

conditions of that certain Share Purchase Agreement by and between,  inter alia,

Assignor and Assignee dated as of September 24, 2003.





Dated: September 24, 2003


                                                     By:  /s/ Lily Wang
                                                        ----------------------
                                                     Name: Lily Wang





                                       91




                                   SCHEDULE C
                                   ----------

                       Stock Ownership Transfer Agreement
                       ----------------------------------



Assignor: Sino Pharma Co., Ltd. (hereinafter referred to as "Party A")
Address: Room 605-6, Chengxin Mansion, #130-136. Middle Gannuo Road, Hongkong
Name of the legal representative: Li Keying Position: Chairman of the Board
Nationality: Singapore
Assignor:  Tangshan Yian Biological  Engineering Co., Ltd. (hereinafter referred
to as ..Party B").
Address: the High and New Technology Development Zone in Tangshan City
Name of the legal representative: Li Keying Position: Chairman of the Board
Nationality: Singapore
Assignor: Beijing Keding Investment Co., Ltd. (hereinafter referred to as "Party
C") Address: Beijing University
Biology Tower, #39, West Shangdi Road. Haidian
District, Beijing
Name of the legal representative: Yin Weidong    Position: Chairman of the Board
Nationality: China
Assignee: Lily Wang (hereinafter referred to as "Party D")
Nationality: America


This agreement is signed by Parry A and Party B on September, 2003 in Beijing.


Party A legally owns 20.95% of the stock ownership of Sinovac Biotech Co., Ltd.
(hereinafter referred to as "Sinovac"). Party B legally owns 15.72% of the stock
ownership of Sinovac. Party C legally owns 6.08% of the stock ownership of
Sinovac. Sinovac is founded on April 28, 2001 with the approval of the
Industrial and Commercial Administration of Beijing Municipality. Party A now
intends to transfer all of its stock ownership of Sinovac, namely 28 million
shares; Party B now intends to transfer all of its stock ownership of Sinovac,
namely 21 million shares; and Party C now intends to transfer part of its stock
ownership of Sinovac, namely 8.12 million shares. The transfer of the stock
ownership by Party A, Party B and Party C has been agreed by other share holders
of Sinovac and been approved by the board of Sinovac according to its meeting
resolution.


Party D herein agree to accept the 57.12 million shares (42.75%) of the stock of
Sinovac transferred by Party A. Party B, and Party C. The board of Sinovac also
agree to Party D's acceptance of the 57.12 million shares (42.75%) of the stock
of Sinovac owned by Party A, Party B, and Party C. Based on the principle of
equality and mutual benefits, Party A. Party B, Party C and Party D reached
following agreements on the transfer of the 42.75% stock ownership. namely 57.12
million shares of the stock of Sinovac owned by Patty A, Party B, and Party C
after friendly consultation:







                                       92




I.        Stock Ownership Transfer Price

Party A, Party B, and Party C jointly agree to transfer their 57.12 million
shares of the stock of Sinovac to Party D with the price of $5.0294 million USD
pursuant to the terms and conditions of this agreement. Party D agree to accept
the 57.12 million shares (42.75%) of the stock of Sinovac owned by Party A,
Party B, and Party C with the price of $5.0294 million USD.


II.       Agreement Violation Liability

1.        If any Party of this agreement failed to fulfill its obligations
          reasonably and completely pursuant to the regulations of this
          Agreement, the violating Party shall bear relative liabilities for the
          violation of the Agreement. Any obligations and damages thus brought
          upon the non-violation Part shall be remedied by the Party violating
          this Agreement.


III.      Modification and Termination of This Agreement


If any one of the following circumstances aroused, this Agreement can be
modified or terminated, however, the modification or termination shall become
valid only after the signing of the modification or termination agreement by
Party A, Party B, Party C and Party D.

1.        It is impossible to carry out the terms and conditions of this
          Agreement due to force majeure, or external causes the Party cannot
          prevent and not resulted from the Party's negligence.

2.        Party A, Party B, Party C and Party D all agree to modify or terminate
          this Agreement after consultation due to the change of conditions.


IV.       Others


This Agreement is in six originals. One for Party A, Party B, Party C, Party D
and Sinovac, and the rest being kept by relative government department.






                                       93




Assignor (Party A) (Seal)  [SINO PHARMA COMPANY LIMITED STAMP]
Legal Representative or Authorized Trustor (singature):
Date:    September 17, 2003

                  /s/ Keying Li
          ------------------------------
                  Keying Li


Assignor (Party B) (Seal)  [STAMP]
Legal Representative or Authorized Trustor (singature):
Date:    September 17, 2003

                  /s/ Keying Li
          ------------------------------
                  Keying Li


Assignor (Party C) (Seal)  [STAMP]
Legal Representative or Authorized Trustor (singature):
Date:    September 17, 2003

                 /s/ Wei Dong Yin
          ------------------------------
                   Wei Dong Yin


Assignor (Party D) (Seal)
Legal Representative or Authorized Trustor (singature):
Date:    September 17, 2003

                   /s/ Lily Wang
          ------------------------------
                     Lily Wang








                                       94




                                   SCHEDULE D
                                   ----------

                       Stock Ownership Transfer Agreement
                       ----------------------------------

Assignor: Shenzhen Bio-port Co., Ltd. (hereinafter referred to as "Party A")

Name of the legal representative: Xianping Wang Position: Chairman of the Board
Nationality: China

Assignee: Lily Wang (hereinafter referred to as "Party B")
Nationality: America

This agreement is signed by Party A and Party B on September 17, 2003 in
Beijing.

Party A legally owns 12.43% of the stock ownership of Sinovac Biotech Co., Ltd.
(hereinafter referred to as "Sinovac"). Sinovac is founded on April 28, 2001
with the approval of the Industrial and Commercial Administration of Beijing
Municipality. Party A now intends to transfer its stock ownership of Sinovac,
namely 11.016 million shares (8.25%). The transfer of the stock ownership by
Party A has been agreed by other shareholders of Sinovac and has been approved
by the board of Sinovac according to its meeting resolution.

Party B herein agrees to accept the 11.016 million shares (8.25%) of the stock
of Sinovac transferred by Party A. The board of Sinovac also agrees to Party B's
acceptance of the 11.016 million shares (8.25%) of the stock of Sinovac owned by
Party A. Based on the principle of equality and mutual benefits, Party A and
Party B, reached the following agreements on the transfer of the 8.25% stock
ownership, namely 11.016 million shares of the stock of Sinovac owned by Party A
after friendly consultation.

I.   Stock Ownership Transfer Price

Party A agrees to transfer its 11.016 million shares of the stock of Sinovac to
Party B for the price of $0.9706 million USD pursuant to the terms and
conditions of this agreement. Party B agrees to accept the 11.016 million shares
(8.25 %) of the stock of Sinovac owned by Party A for the price of $0.9706
million USD.

II.  Agreement Violation Liability

1.   If any Party of this agreement failed to fulfill its obligations reasonably
     and completely pursuant to the regulations of this Agreement, the violating
     Party shall bear relative liabilities for the violation of the Agreement.
     Any obligations and damages thus brought upon the non-violation Party shall
     be remedied by the Party violating this Agreement.

III. Modification and Termination of This Agreement

If any one of the following circumstances aroused, this Agreement can be
modified or terminated, however, the modification or termination shall become
valid only after the signing of the modification or termination agreement by
Party A and Party B.
1.It is impossible to carry out the terms and conditions of this Agreement due
to force majeure, or external causes the Party cannot prevent and not resulted
from the Party's negligence.
2.Party A and Party B all agree to modify or terminate this Agreement after
consultation due to the change of conditions.






                                       95




IV.  Others

This Agreement is in four originals, one for Party A, Party B, and Sinovac, and
the rest being kept by the relative government department.


Assignor (Party A) (Seal): [stamp]
Legal Representative or Authorized Trustor (signature):

                /s/ Xianping Wang
          ------------------------------
                   Xianping Wang



Assignee (Party B) (Seal):
Legal Representative or Authorized Trustor (signature):

                    /s/ Lily Wang
          ------------------------------
                      Lily Wang








                                       96




                                   SCHEDULE E
                                   ----------

            DESIGNEES OF THE NEWLY-ISSUED CAPITAL STOCK OF NET FORCE
            --------------------------------------------------------

                                                Number of Shares to be
Name        Address                             Issued by Net Force
- ----        -------                             ----------------------

Lily Wang   Suite 202 - 300 Murchinson Dr.           10,000,000
            Millbrae, CA 94030
            USA