Objective To evaluate the efficacy and safety of adefovir dipivoxil for elderly patients (age≥65 years) with chronic hepatitis B.Methods Ninety patients with chronic hepatitis B were divided into two groups: the elderly group (30 cases,age ≥65 years) and the non-elderly group (60 cases,age <65 years).All subjects received oral administration of adefovir dipivoxil (10 mg/d).The laboratory data,such as the hepatic functions,serum HBV DNA levels,renal function,glucose,total cholesterol and blood routine indices,were compared between the two groups before and at 4,8,12,24,36,48 weeks after adefovir dipivoxil administration.Results At 48 weeks after adefovir dipivoxil administration,the normalization rates of hepatic function in elderly group and non-elderly group were 76% (13/17) and 80% (28/35),separately,and it took (78±73) and (69±53) days respectively for the patients in two groups to recover to normal hepatic fucntion(P>0.05).The sero-conversion rates of HBV DNA were 83%(25/30) and 73%(44/60 in two groups),respectively ,and it took (124±75) and (145±76) days respectively for serum HBV-DNA being suppressed within undetectable level in two groups(P>0.05).There was no difference in sera creatinine between the two groups at all time points.However,at 48 weeks,there were 2 cases who had serum creatinine higher than the normal upper limit in non-elderly group,and treatment changed for one case.No other adverse effect was observed in all patients.Conclusion Adefovir dipivoxil for treatment of chronic hepatitis B is safe and effective for non-elderly patients,as well as for the elderly patients.