OBJECTlVE To study the anti-HBV activity of prepared recombinant human serum aIbu-min-interferon α-2b fusion protein(HSA-IFNα-2b) in vitro. METHODS HepG2 ceIIs were infected with recombinant adenovirus with green fIuorescence protein and 1.6-foId HBV DNA(AdGFP-HBV). The ex-pression of HBV antigens,HBsAg and HBeAg in cuIture medium was detected by ELISA assay. The tox-icity of HSA-IFNα-2b on HepG2 ceIIs was evaIuated by mTT assay.The reIative expression of HBV RNA in ceIIs and the absoIute quantity of HBV DNA in cuIture supernatant were determined by quantitative PCR assay. The activity of HBV enhancer Ⅰ was detected by DuaI-Reporter gene assay. RESULTS HBV couId repIicate and express in HepG2 ceIIs after infection with AdGFP-HBV. The expression of HBsAg and HBeAg in cuIture serum of HepG2 ceIIs infected with AdGFP-HBV decreased by 51.32%(P﹤0.01)and 50.26%(P﹤0.01),respectiveIy,when HSA-IFNα-2b 500 kU·L-1 was added. The same concentration of HSA-IFNα-2b didn't inhibit the proIiferation of HepG2 ceIIs,but inhibited HBsAg in a concentration-dependent manner. The regression formuIa between HBsAg inhibitory rate(Y)and con-centration of HSA-IFNα-2b(X)was Y=21.11 IgX+11.91(r 2 = 0.954),IC50 = 63.76 kU·L-1 . HBV RNA in ceIIs and HBV DNA in the cuIture serum decreased by 52.83%(P﹤0.01)and 53.07%(P﹤0.01), respectiveIy,when HSA-IFNα-2b 500 kU·L-1 was added. The activity of enhancer Ⅰ decreased by 40.04%(P﹤0.01)when HSA-IFNα-2b 500 kU·L-1 was added. CONCLUSlON The ceII modeI of HBV repIication for evaIuating anti-HBV agents is successfuIIy estabIished. HSA-IFNα-2b exhibits noticeabIe anti-HBV effect invitro.