Abstract： Objective To determine the relationship between the polymorphism of D2S140 gene and type 2 diabetes mellitus.Methods D2S140 region polymorphism were analyzed with the polymerase chain reaction and short tandem repeat methods in 103 subjects with type 2 diabetes mellitus and 105 nondiabetic subjects.All subjects were biologically unrelated Chinese without a family history of DM.Results There were 7 alleles ranging from 151bp to 163bp in all subjects.The frequencies were 0.01 to 0.37,2 alleles were more common in diabetic patients than in nondiabetic subjects (RR=16.04, P <0.001) and 6 alleles were less frequent in diabetic patients than in nondiabetic subjects (RR=0.23, P <0.001).Logistic regression analysis showed that the 2 alleles of D2S140 gene are main risk factors for type 2 diabetes mellitus.Conclusion Polymorphic microastellite repeat marker at the D2S140 gene locus is positively associated with type 2 diabetes mellitus in Chinese.