C. Zhao 1,2 , W. Zhang 2,3 , X.C. Tian 1 , C.Y. Fang 2,3 , H.J. Lu 2,3 , P.Y. Yang 2,3 , Y.M. Wen 1,2 Background/Aims: Hepatitis B virus (HBV) is still regarded as one of the major causes of chronic hepatitis, cirrhosis and hepatocellular carcinoma worldwide. The interactions between hepatitis B surface antigen (HBsAg) and host cells still remain largely unknown and need to be explored in detail. Methods: Differential protein expression profiles of HepG2-S-G2( Stably expressing HBsAg cell line) and HepG2-Neo-F4 ( control cell line) were compared using two dimensional gel based differential proteomic approach. Cell proliferation assay and survival assay were used for further studies on the candidate protein.