Twelve S-substituted 7-mercapto-4-methylcoumarin analogs were synthesized and evaluated for the inhibition to HBV in HepG2 2.2.1.5 cell. Among them, ten compounds exhibited potent inhibition to HBsAg and/or HBeAg with the IC 50 values of sub-μmol/L level. The IC 50 of anti-HBsAg activities of 5c and 5j reached 0.01μmol/L respectively which were 16 fold more potent than that of 3TC. Compounds 3, 5e, 5g, 5h and 5i showed admirable inhibitory activity to both HBsAg and HBeAg. The bioassay results indicated the S-substituted 7-mercapto-4-methylcoumarin analogs merit attention as novel anti-HBV agents.