Objective： To explore the relationship between microsatellite DNA polymorphism of human PON1 gene and type 2 diabetes mellitus in Chinese population of Nanjing. Methods： Among Chinese people of Han nationality in Nanjing，119 patients with type 2 diabetes mellitus and 116 nondiabetic subjects were collected randomly. Polymorphism of microsatellite marker was detected by polymerase chain reaction，polyacrylaimde gel electrophoresis and silver staining to investigate the frequency distribution of PON1 gene microsatellite（GT） in patients with type 2 diabetes mellitus or nondiabetic subjects. Results：The GT sequences in four types of alleles were repeated for 12，15，17，20 respectively. The PON1 gene alleles frequencies in patients with type 2 diabetes mellitus were significantly different from that in control subject（χ2 = 14.10，P < 0.01）. Conclusion：polymorphism of microsatellite markers in PON1 gene may be associated with type 2 diabetes in Han people.