6-K

FORM 6-K

SECURITIES AND EXCHANGE COMMISSION
Washington D.C. 20549

REPORT OF FOREIGN ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16 OF THE
SECURITIES EXCHANGE ACT OF 1934

For the month of May 2008
__________

Commission File Number: 001-32371
__________

SINOVAC BIOTECH LTD.

39 Shangdi Xi Road
Haidian District
Beijing 100085, People’s Republic of China
(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F     ___X____          Form 40-F           _________

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):________________

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):________________

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes  ________                                      No   ___X____

If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b):

82-  ____N/A____

SINOVAC BIOTECH LTD.

Form 6-K

TABLE OF CONTENTS

                                                                                                                                                Page

Signature                                                                                                                                    3
Exhibit 99.1 – Press Release                                                                                                       4

SIGNATURE

          Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.


                                                                                          SINOVAC BIOTECH LTD.


                                                                                          By:      /s/ Weidong Yin                           
                                                                                          Name:  Weidong Yin
                                                                                          Title:     Chief Executive Officer, President


Date:  May 14, 2008

EX-99.1

Exhibit 99.1

Sinovac to Host Conference Call to Report First Quarter 2008 Financial Results
Thursday May 15, 8:00 am ET

BEIJING, May 15 /Xinhua-PRNewswire/ -- Sinovac Biotech Ltd. (Amex: SVA - News), a leading provider of vaccines in China, today announced that it will host a conference call on Friday, May 16, 2008 at 9:00 a.m. ET to review the Company's first quarter financial results for the period ended March 31, 2008 and provide an update on recent corporate developments.

To access the conference call, please dial 1-877-407-4018 (USA) or 1-201-689-8471 (international). A replay of the call will be available from 11:00 a.m. ET on May 16, until May 30, 2008 at midnight. To access the replay, please dial 1-877-660-6853 (USA) or 1-201-612-7415 (international) and reference the account number 3055 and the access code 285507.

A live audio webcast of the call will also be available from the Investors section on the corporate web site at http://www.sinovac.com. A webcast replay can be accessed on the corporate website beginning May 16, 2008 and the replay will remain available for 30 days.

About Sinovac

Sinovac Biotech Ltd. is a China-based biopharmaceutical company that focuses on the research, development, manufacture and commercialization of vaccines that protect against human infectious diseases. Sinovac's commercialized vaccines include Healive® (hepatitis A), Bilive® (combined hepatitis A and B), Anflu® (influenza) and Panflu(TM) (H5N1). Sinovac is currently developing Universal Pandemic Influenza vaccine and Japanese encephalitis vaccine. Additional information about Sinovac is available on its website, http://www.sinovac.com . To be added to our distribution list, please email: info@sinovac.com.


For more information, please contact:

Helen G. Yang
Sinovac Biotech Ltd.
Tel:   +86-10-8289-0088 x871
Fax:   +86-10-6296-6910
Email: info@sinovac.com

Investors/Media:
Stephanie Carrington/Janine McCargo
The Ruth Group
Tel:   +1-646-536-7017/7033
Email: scarrington@theruthgroup.com
jmccargo@theruthgroup.com