Abstract: Objective To explore the correlation between polymorphism of cytotoxic T lymphocyte antigen-4（CTLA-4）+49A／G and susceptibility to breast cancer. Methods All eligible case-control studies published up to June 2014 were searched out from PubMed， MEDLINE， Web of Science， EMBASE， CNKI and WanFang databases. Two reviewers independently identified the literature，extracted data and assessed the quality of included studies according to inclusion and exclusion criteria. Meta-analysis was performed using RevMan51 software to analyze. Results A total of 5 studies comprising 3237 patients and 3242 controls were finally included. The included studies showed good homogeneity in the four genetic models of AA vs.GG，AG vs.GG，AG／AA vs.GG，A vs.G. There was significant association between CTLA-4+49A／G polymorphism and breast cancer susceptibility（AA vs.GG：OR=1.49， 95％CI：1.10-2.00； AG vs. GG：OR=1.23， 95％CI：1.10-1.37；AG／AAvs.GG：OR=1.27， 95％CI：1.14-1.40；A vs.G：OR=1.19， 95％CI：1.11-1.29）. Conclusion There is significant association between polymorphism of CTLA-4+49A／G and susceptibility to breast cancer.