Objective To investigate the therapeutic effects of recombinant yeast hepatitis B virus(HBV)vaccine combined with interferon(IFN)α-1b and determine the rational dosage of HBV vaccine for the further clinical study with larger sample.Methods Two hundreds and sixteen patients with chronic hepatitis B(CHB)were enrolled in this randomized,multi-center,double-blinded and placebo-controlled clinical trial.All the subjects were not treated with antiviral drugs within 6 months and randomly divided into 90μg,60μg and placebo groups with a ratio of 1:1:1.All the patients were intramuscularly administrated with 90μg or 60μg recombinant HBV vaccine or placebo at week 0,2,6,10,14,18,22,respectively.Meanwhile,they were also treated with IFNα-1b 50μg,3 times a wcek for 24 weeks.All patients were followed up for 24 weeks after withdrawal of anti-HBV therapy.Serum HBV DNA level,HBeAg titer and liver function were monitored frequently.Interferon-γ secreting lymphoeytes were detected by Enzyme-linked immunospot(ELISPOT)in part of the patients.Results The serum HBV DNA levels were(6.03±1.79),(5.52±1.82)and(6.29±1.70)log10 copy/mL at week 24 of treatment in high dose,low dose and placebo groups,respectively (P=0.458).And the serum HBV DNA levels were(5.92±1.98),(5.49±1.99)and(6.16±1.76)log10 copy/mL at weck 24 after withdrawal of treatment,respectively(P=0.720).The rates of patients whose HBV DNA＜1×105 copy/mL in these three groups were 30.4%,39.4% and 20.8% at week 24 of treatment,respectively and there was significant difference between high dose group and low dose group(P=0.015).The rate of patients whose HBV DNA＜1×105 copy/mL at week 24 after withdrawal was highest in low dose group,but no significant differences before and after treatment in these three groups(P=0.257).The HBV DNA negative rates were 17.4%,25.4% and 6.9% in these three groups,respectively,which were significantly different(P=0.012).At week 24 of treatment and week 24 after withdrawal of treatment,the alanine aminotransferase normalization rate,HBeAg seroconversion rate were highest in low dose group,but no significant differences in these three groups.ELISPOT positive rates at week 24 of treatment and week 24 after withdrawal of treatment in high close and low dose groups were higher than that in placebo group(P＜0.05).The incidence of adverse events was similar and there was no drug related severe adverse events in each group.Conclusion Recombinant HBV vaccine maybe contribute to anti-HBV therapy and 60μg of dosage seems to be rational.