Objective To observe the efficacy and safety of lamivudine in the treatment of HBV infection. Methods 237 cases of HBV infection were divided into two groups randomly. 128 patients of group A were administered lamivudine 150mg a day for 48 weeks and routine nonspecific drugs. 109 patients of group B were administered only routine nonspecific drugs. HBV serological markers, HBV DLT and ALT were measured at 8th,16 th 24th,48th week. Results In the group A, HBV DNA negative conversion rates at 8th,16th,24th and 48th weeks after treatment were 52 3%,82 0%,96 1% and 89 1% respectively, which were higher than those in the group B(P