Objective To evaluate the efficacy of lamivudine and thymosin alpha-1 combination therapy in the treatment of HBeAg-posi-tive chronic hepatitis B (CHB)by meta-analysis.Methods Randomized controlled trials (RCTs)of lamivudine and thymosin alpha-1 combination therapy in treatment of HBeAg-positive CHB (follow-up for at least 24 weeks),from January 1998 to date,were identified by searching Cochrane Library,PubMed,EMBASE,EBSCO,CNKI,Wanfang Data,and CQVIP.Lamivudine monotherapy RCTs were searched for in the same way as control tests.Efficacy was measured by odds ratio.Meta-analysis was carried out with RevMan 5 .2 soft-ware.Results Nine RCTs involving 600 patients were included,with 320 cases in the combination therapy group and 280 in the control group.At the end of follow-up,the combination therapy group had significantly higher serum ALT recovery rate,HBV -DNA negative conversion rate,HBeAg negative conversion rate,and HBeAg seroconversion rate than the control group (P<0.01 for all),with pooled odds ratios (95% confidence intervals)of 4.84 (3.28,7.16),2.09 (1.45,3.01),5.32 (3.35,8.46),and 6.22 (3.78,10.25), respectively.Conclusion Lamivudine and thymosin alpha-1 combination therapy is more likely to achieve sustained response rate than lamivudine monotherapy for HBeAg-positive CHB.More RCTs of high quality and large scale are required to verify this conclusion.