Abstract: Objective To study the therapeutic efficacy of 48-week entecavir treatment in patients with decompensated hepatitis B cirrhosis.Methods Patients with decompensated hepatitis B cirrhosis were randomly divided into two groups as entecavir group (patients treated with entecavir 0.5 mg per day) , and lamivudine group (patients treated with lamivudine 100 mg per day) .Serum levels of ALT, AST, Alb, TBil, HBeAg, HBV DNA, PC, IVC, LN and HA, renal function tests and Child-Pugh scores of the two groups were observed and analyzed at 24th and 48th weeks.Results At week 24 ALT, AST, Alb, TBil, PTA, serum markers of hepatic fibrosis and Child-Pugh score were improved;however, there was no significant difference between the two groups (P > 0.05) .The rates of HBeAg/anti-HBe seroconversion were 26.1% (6/23) and 30.4% (7/23) at week 24 and 48 in entecavir group, respectively.But there was no statistically significant difference between the two groups (P > 0.05) .The mean reduction of serum HBV DNA and the proportion of patients with undetectable serum HBV DNA were greater in entecavir group than lamivudine group (P < 0.05) at week 24 and 48.Conclusion Entecavir can rapidly and effectively inhibit the replication of HBV in patients with decompensated hepatitis B cirrhosis and improve the liver function.