Abstract: OBJECTIVE To explore the effect of Xiao Chaihu decoction on liver function and HBV-DNA copies of patients with hepatitis B virus (HBV) infection.METHODS A total of 96 patients with HBV infection who were hospitalized in hepatopathy department and treated in outpatient department from Apr 2012 to Nov 2015 were enrolled in the study and divided into the control group and the experimental group, with 48 cases in each group. The control group was treated with conventional antiviral therapy, liver protection and reduction of enzymes, while the experimental group was given additional Xiao Chaihu decoction on basis of the above treatment, both groups were treated for 4 weeks as a course. The liver function, HBV-DNA copies, hepatic fibrosis indexes and T lymphocytes subsets were determined before and after the treatment, and the clinical curative effect and incidence of adverse reactions were observed and compared between the two groups of patients.RESULTS The levels of serum AST, ALT, TBiL and HBV-DNA copies of the two groups of patients were lower after the treatment than before the treatment, the levels of serum HA, ⅣC, PCⅢ and LN of the two groups of patients were lower after the treatment than before the treatment, the levels of serum CD₄⁺ and CD₄⁺/CD₈⁺ were higher after the treatment than before the treatment, and the CD₈⁺ level was lower after the treatment than before the treatment(P＜0.05). The levels of serum AST, ALT, TBiL and HBV-DNA of the experimental group were lower than those of the control group after the treatment; the levels of serum HA, ⅣC, PCⅢ and LN of the experimental group were lower than those of the control group after the treatment, the levels of serum CD₄⁺ and CD₄⁺/CD₈⁺ of the experimental group were higher than those of the control group after the treatment, and the CD₈⁺ level of the experimental group was lower than that of the control group (P＜0.05). The response rate of the control group was 77.08%, lower than 91.67% of the experimental group (P＜0.05). CONCLUSION Xiao Chaihu decoction may raise the curative effect of the patients with HBV infection, remarkably improve the liver function and reduce the hepatic fibrosis and HBV-DNA copies, with the safety satisfied, and it is effective for the treatment of the patients.