OBJECTIVE To survey the therapeutic effect of lamivudine alone or in combination with bicyclol on chronical viral hepatitis B.METHODS Ninety patients with chronic viral hepatitis B were divided into 3 groups: A,B and C.Patients of group A(n=30) were given each 100mg lamivudine po qd,and 25 mg(bicyclol) po,tid,and the course of treatment lasted 72 weeks.Patients of group B(n=30) were subjected to(lamivudine) treatment alone at the same dosage as that of patients in group A.Patients of group C(n=30) were treated with(conventional) hepatinica and symptomatic therapeutic measures,serving as controls.Changes in serum HBV DNA and liver functions and YMDD mutant were dynamically monitored.RESULTS At the end of the 24,48 and 72 weeks of treatment,the rates of sera to turn negative for HBV DNA were 90.0%,(86.7%,) and(83.3%),(respectively),in patients of group A,and 86.7%,83.3%,and 76.7%,respectively,in patients of group B.The rates of sera to turn negative for HBV DNA,in patients of groups A and B were significantly higher than those in patients of group C(P0.05);at the end of 72 weeks,the rates of YMDD mutant were 16.7% in group A and 36.7% in group B,the rates in group A were significantly higher than in group B((P