Abstract： Objective To compare the 2-year efficacy of de novo combination therapy with lamivudine (LAM) and adefovir dipivoxil (ADV) to that of entecavir (ETV) monotherapy in treatment of patients with hepatitis B virus ( HBV )-related decompensated cirrhosis.Methods A total of 120 naive patients with HBV-related decompensated cirrhosis admitted to Shangyu People's Hospital and the First Affiliated Hospital of Zhejiang University from January 2007 to April 2008 were enrolled,in which 60 were treated with LAM and ADV combination therapy,and other 60 patients were treated with ETV monotherapy.Tests for liver and kidney function,alpha-fetoprotein,HBV serum markers,HBV DNA load,prothrombin time (PT),and ultrasonography or CT scan of liver were performed every 1-3 months.Repeated measure ANOVA and x2test were used to compare the efficacy,side effects and accumulated survival rates at 12 and 24 month in two groups.Results Forty-five patients in each group were followed-up for 24 months.There was no significant difference in HBV DNA negative rates and ALT normalization rates at month 12 (x2 =2.12 and 2.88,P ＞0.05 ) and month 24 between two groups (x2 =3.21 and 3.24,P ＞ 0.05); while HBeAg seroconversion rate in LAM + ADV group at month 24 was significantly higher than that in ETV group (43.5％ vs.36.4％,x2 =4.09,P＜0.05).Viral breakthrough occurred in 2 cases (4.4％) by month 12 and 3 cases (6.7％) by month 24 in LAM + ADV group,and no viral mutation was observed; while in ETV group,viral breakthrough occurred in 1 case ( 2.2％ ) by month 12 and 2 cases (4.4％) by month 24,and viral mutation was observed in 1 case (2.2％) by month 24.At the end of month 24,increase of AIb (F=18.9 and 17.3,P＜0.05),decrease of TBil and ALT (F=16.5,17.1 and 23.7,24.8,P ＜0.05 ),shortening of PT ( F =22.7 and 24.5,P ＜ 0.05 ),and the improvements of CTP and MELD scores (F=18.5,17.8 and 24.2,23.8,P＜0.05) were observed in both groups.The accumulative rates of mortality or liver transplantation were 16.7％ ( 10/60 ) and 18.3％ ( 11/60 ) in LAM + ADV and ETV groups,respectively.No blood creatinine increased above the normal upper limit was observed in both groups.Conclusion Both LAM + ADV combination therapy and ETV monotherapy can effectively inhibit HBV replication,improve liver function,decrease mortality and viral resistance,but the 24-month HBeAg seroconversion rate in combination therapy group is higher than that in monotherapy group.