Exhibit 8.1

List of Subsidiaries

1. Sinovac Biotech (Hong Kong) Limited., a Hong Kong company

2. Sinovac Biotech Co., Ltd., a PRC company

3. Sinovac Life Sciences Co., Ltd., a PRC company

4. Sinovac (Dalian) Vaccine Technology Co., Ltd., a PRC company

5. Sinovac Biomed Co., Ltd., a PRC company

6. Sinovac Life Sciences (Hainan) Co., Ltd., a PRC company

7. Sinovac Yidao Biomed Co., Ltd., a PRC company

8. Kaixin Zhitong Health Technology Co., Ltd., a PRC company

9. Sinovac Yidao Development Co., Ltd., a PRC company

10. Sinovac Biotech (Singapore) Pte. Ltd., a Singapore company

11. Sinovac Biotech (Chile) SpA, a Chile company