【Abstract】 Objective To investigate the efficacy and safety of S1 plus oxaliplatin versus capecitabine plus oxaliplatin for firstline treatment of patients with advanced colorectal cancer．Methods Computerbased retrieval was performed on Pubmed, Embase,Medline,Cochrane Library,CBM,VIP,CNKI and Wanfang Database．Papers were selected according to the inclusion and exclusion criteria. After collecting the data and evaluating the methodological quality of the included studies, RevMan 53 software was used to perform Metaanalysis.Results 11 ＲCTs involving 1439 patients were included.Metaanalysis indicated that the objective response rate (OR=125, 95% CI:098～160,P=007) and disease control rate (OR=121, 95% CI:091～162,P=02)， showed no statistical significance between S1 combined with oxaliplatin and oxaliplatin combined with capecitabine. For adverse reactions，S1 combined with oxaliplatin could increased incidence of grade 14 anorexia (P=001), oral mucositis (P=002)，but decrease the incidence of grade 34 liver function damage (P=001) and the incidence of hand foot syndrome (grade 14: P＜000001; grade 34: P=001). There were no statistical difference between the two regimen in other adverse reactions.Conclusion Compared with capecitabine combined with oxaliplatin, S1 combined with oxaliplatin seem to have similar shortterm efficacy in the firstline treatment for advanced colorectal cancer．However, S1 combined with oxaliplatin has a lower incidence of toxicities.