Objective To explore the relationship of the K121Q polymorphism of membrane glycoprotein PC-1 gene with the features of insulin resistance(IR) and type 2 diabetes mellitus(T2DM).Methods The K121Q polymorphism in exon 4 of PC-1 gene were determined with the technique of polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) in 133 patients with T2DM and 108 controls with normal glucose tolerance(NGT) in Shenzhen city.The clinical and laboratory data were also compared between type 2 diabetic patients with different genotypes.Results No statistically significant differences were observed in the genotype and allele frequencies between the control and the T2DM subjects.The concentrations of fasting plasma glucose(FPG),triglycerides(TG) and C-peptide were higher in T2DM patients with KQ genotype than with KK genotype(P