Abstract: Objective To evaluate the effect of acarbose and metformin on body mass reduction.Methods Clinical randomized control trials regarding acarbose and metformin reducing body mass were searched in databases of PubMed,Embase,China Biology Medicine (CBM),China National Knowledge Infrastructure (CNKI),China Science and Technology Journal Database(VIP) and Wanfang Data from their inception to January 2016.Clinical data were evaluated.Review Manager 5.2 software was used for statistical analysis.Results Finally 7 literatures with 983 patients were included.Meta-analysis showed that the effect of acarbose on reducing body mass was better than that of metformin(mean difference =-0.94,95% confidence interval:-1.24 to-0.65,P < 0.000 01).Conclusion Acarbose is superior to metformin in reducing body mass.