Objective To systematically evaluate the correlation between type 2 diabetes mellitus (T2DM) in Chinese population and K121Q polymorphism in exon-4 of plasma cell glycoprotrin-1 (PC-1) gene. Methods The following databases such as CNKI, VIP, CBM, PubMed, EMbase, The Cochrane Library (Issue 3, 2012) and WanFang Data were searched to collect case-control studies on the correlation between T2DM and K121Q polymorphism in exon-4 of PC-1 gene. The retrieval time was from 1980 to 2012. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data and assessed the quality. Then the meta-analysis was conducted by using RevMan 5.0 and Stata 12.0 software, and the publication bias was analyzed by means of Egger’s linear regression. Results A total of 11 studies involving 1 637 T2DM patients and 1 730 healthy volunteers were included. The results of meta-analyses showed that, for Chinese population, the risk of T2DM was higher in those with K/Q genotype than K/K genotype (OR=1.84, 95%CI 1.19 to 2.85, P=0.006), in Q/Q+K/Q genotype than K/K genotype (OR=1.92, 95%CI 1.18 to 3.14, P=0.009), and also in allele Q than allele K (OR=1.83, 95%CI 1.16 to 2.89, P=0.010). Conclusion The K121Q polymorphism in exon-4 of PC-1 gene in Chinese population is significantly associated with T2DM. For the quantity and quality limitation of the included studies, this conclusion has to be further proved by more studies.