Objective To have a good understanding of insulin resistance in type 2 diabetes. Methods Four families with type 2 diabetes and fifty-two type 2 diabetic patients, fifty-four non-diabetic healthy subjects were examined with the technique of PCR-SSCP and DNA direct sequencing in exon 17 and 20 of insulin receptor gene. Results In exon 17, the frequency of the variation in codon 1008 (Gly GGC→GGT) was 18.0%, 29.4%and 9.3%(χ2=12.713 3, P<,0.000 5) in pedigrees, patients and controls respectively. The relative risk (RR) in pedigrees and diabetic patients was 1.944 and 3.738 in comparison with controls group. Linkage analysis in the pedigrees show the maximal LOD score was 0.465 736 (θ=0.000 0). In exon 20, the frequency of the variation in codon 1169 (Gly GGT→GGC) was 10.0%, 15.4%and 3.7%(χ2=3.236, P>,0.05). The RR was 2.700 and 3.927 in pedigrees and diabetic patients in comparison with controls group. Linkage analysis in the pedigrees show the maximal LOD score was 1.803 34 (θ=0.000 0). Conclusion The results suggest the two detected variations in GLY1008and GLY1169might be genetic markers for susceptibility to type 2 diabetes.