Abstract： ObjectiveTo investigate the relationship betwe en 16189 variant (T→C transition) of mitochondrial DNA and pathogenesis of type 2 diabetes in Chinese.MethodsPCR and RFLP were used to detect the 16189 variant of mtDNA in 308 unrelated Shanghai Chinese,including 158 indi viduals with normal glucose tolerance and 150 patients with type 2 diabetes.ResultsThe prevalence of 16189 variant in Shanghai Chinese was h igher than that in white people in the United Kingdom(29% vs 9.9%,P=6.85×1 0 -6 ). The diabetic patients with 16189 variant had lower HOMA-IR level co mpared with those without 16189 variant. furthermore, stepwise multiple regressi on analysis showed the 16189 variant was one of the independent factors contribu ting to HOMA-IR.Conclusion16189 variant (T→C transition) of mtDNA is associ ated with insulin resistance,which is important in the development of type 2 dia betes in Chinese population.