Type2 diabetes is a genetically heterogenous disease with various combinations of susceptibility genes.Environmental factors such as obesity,multible genes are responsible each contributing a small amount to overall risk.Insulin resistance is considered to be very risk factor for type2 diabetes.Several studies on various population reported that small size at birth coupled with subsequent obesity increases risk for insulin resistance syndrome in later life.Aim of this study is to find out mutations in the candidate genes responsible for type2 diabetes.Here we have discusssed about the causes of type2 diabetes,its symptoms pathogenesis,diagnosis and associated diseases.With the help of Candidate gene approach PPARg gene is found to be a candidate gene for type 2 diabetes. Exonic regions of PPARg gene was sequenced for polymorphisms.Pro 12 Ala Polymorphism and C161T polymorphism were examined and their association with type2 diabetes was studied.