Abstract: Objective To understand the association between plasminogen activator inhibitor-1 (PAI-1) gene 4G/5G polymorphism and type 2 diabetic nephropathy (DN) in Chinese Han patients in Guangdong Province. Methods PAI-1 gene 4G/5G polymorphism was analyzed in 26 normal individuals, 77 patients with type 2 diabetic nephropathy and 70 type 2 diabetic patients without nephropathy (DNN) by polymerase chain reaction-restriction fragment length polymorphism. Results The 4G/4G genotype frequencies of PAI-1 gene were higher in DN than in DNN patients (0.390 vs 0.171, χ²=13.008, P<0.01), with the odds ratio (OR) of 1.447 (95% confidence interval: 0.533-3.934, P<0.05) in comparison with 5G/5G genotypes between the 2 patient groups. The 4G allele frequencies of PAI-1 gene were similar in DN and DNN groups (0.57 vs 0.51,χ²=1.22, P>0.05). Conclusion The PAI-1 4G/4G genotype is associated with increased risk for type 2 DN the Chinese Han population in Guangdong Province, and type 2 diabetic patients with 4G/4G PAI-1 genotype are more likely to develop DN than those with 5G/5G PAI-1 genotype.