Objective To evaluate the relationship between the single nucleotide polymorphisms (SNPs) of the adiponectin gene +45 in exon 2 and type 2 diabetes mellitus (T2DM) in Chinese population via meta-analysis. Methods Databases including PubMed, Ovid, CBM, VIP, CNKI, and WanFang Data were searched from inception to June 2012, and the references of articles were also retrieved to collect case-control studies about the correlation of SNPs of the adiponectin gene +45 in exon 2 and T2DM in Chinese population. According to the self-designed inclusion and exclusion criteria, two reviewers screened articles, extracted data, and assessed the quality of the included studies independently. Then meta-analysis was performed STATA 11.0, with stability evaluated by both stratified analysis and sensitivity analysis. Moreover, Begg’s funnel plot and Egger’s method were used to assess the published bias of articles. Results 21 articles involving 22 studies were included (3272 T2DM cases and 2597 controls). There were significant differences between the two groups in dominant, recessive and addictive genetic models, and the pooled ORs (95% CI) were 1.36 (1.04, 1.78), 2.07 (1.55, 2.75), and 2.44 (1.59, 3.75), respectively. Conclusion The genetic single nucleotide polymorphisms of the adiponectin +45 in exon 2 is associated with type 2 diabetes in Chinese population. G allele of APM1 is a risk factor for type 2 diabetes, no matter in dominant, recessive or addictive genetic models.