Abstract: Objective To determine the relationship of the Gly972Arg polymorphism of insulin receptor substrate 1 (IRS 1) gene with type 2 diabetes mellitus in Chinese population. Methods Genotype was evaluated by the polymerase chain reaction restriction fragment length polymorphism in 102 pairs of case control spouses. Results The frequency of Gly972Arg mutation of IRS 1 gene was 2% in type 2 diabetic patients and control subjects in Chinese, lower than in Caucasian population. Conclusion Gly972Arg polymorphism of the IRS 1 gene may not play an important role in the Chinese Han population.