Abstract: Objective:To evaluate the efficacy and safety of entecavir to chronic hepatitis B(CHB).Methods:Fifty-three patients who had been treated with entecavir(0.5 mg/d) for 12 months were divided into three groups:HBV DNA 107～109 copies/L,HBV DNA 105～106 copies/L,HBV DNA 104 copies/L.Fasting venous blood were collected from each patient after treatment of 1,3,6 and 12 months for detection of hepatitis B viral(HBV) load DNA,alanine aminotransferase(ALT),aspartate transaminase(AST).Results:As the duration of treatment,HBV DNA,ALT,and AST all decreased significantly(P 0.05).three markers were all significantly lower after 1 month treatment than before treatment.Three markers were also significantly lower after 3 month treatment than that after 1 month treatment.As well as,three markers were significantly lower after 12 month treatment than that after 3 month treatment.Additionally,compared with high viral loads group,HBV DNA,ALT,and AST converted negative earlier in lower viral loads group(P 0.05 to P 0.01).Conclusions:Entecavir can suppress HBV replication and improve liver function of the patients.