Objective To develop a rat model of type 2 diabetic mellitus. Method\ 8 weeks old SD rats were injected with low dose STZ after high calorie given for two months.Then insulin\|glucose tolerance test,islet immunohistory and other corresponding tests were performed and analysed.The data were compard to the others such as purely low dose STZ,high dose STZ and high calorie.Results\ In this rat model,insulin sensitivity decreased,and the synthesis and excretion of insulin were lower than that of purely high calorie group but still higher than that of normal one.Conclusion\ This model owned the characters of mild impaired islet function and insulin resistance which resembled the clinical phenotype of type 2 diabetes,and it would help deepen the mechanical investigation of diabetes and its chronic complication.