Background:Entecavir (ETV) has been shown to be effective in randomized controlled trials in highly selected patients with hepatitis B virus (HBV) infection.This study aimed to evaluate the efficacy of ETV in chronic hepatitis B (CHB) patients in the real-world setting.Methods:A total of 233 treatment-na(i)ve,CHB patients who received at least 12 months of ETV treatment were included in this retrospective study.Rates of virological response (VR),hepatitis B s antigen (HBsAg) loss,hepatitis B e antigen (HBeAg) clearance/seroconversion,virological breakthrough,cirrhosis,and hepatocellular carcinoma were evaluated.Results:Of 233 patients,175 patients were male,with mean age of 43 years old,and 135 patients were HBeAg positive.The mean baseline levels of serum alanine aminotransferase and HBV DNA in all patients were 230 U/L and 6.6 log 10 IU/ml,respectively.The mean follow-up period was 28 months.The cumulative rates of achieving VR increased from 3.4％ at 3 months to 94.4％ at 60 months.Primary nonresponse occurred in 3 (1.3％) patients.Partial VR (PVR) occurred in 61 (26.2％) patients at 12 months.The baseline serum HBV DNA level (hazard ratio [HR],2.054;P ＜ 0.001) was an independent risk factor for PVR.HBsAg loss did not occur.The cumulative rates of HBeAg clearance increased from 2.2％ at 3 months to 28.2％ at 60 months.PVR was the significant determinant of HBeAg clearance (HR,0.341;P =0.026).Age (HR,1.072;P =0.013) and PVR (HR,5.131;P =0.017) were the significant determinants of cirrhosis.Conclusions:ETV treatment was effective for HBV DNA suppression in this study,but HBsAg loss and HBeAg clearance/seroconversion rates were lower compared with previous clinical trials.PVR was associated with HBeAg clearance and cirrhosis.