- For inclusion in the study, participants will be；① Antidiabetic drugs naïve Type 2 diabetes mellitus（WHO standard） with diet control more than 2 weeks; ②or diagnosed Type 2 diabetes mellitus with no oral antidiabetic drugs more than 6months; ③or Type 2 diabetes mellitus treated with insulin secretagogues more than 1 month; all patients have HbA1c between 7.0-10.0% and fasting glucose between 7.0mmol/L～13.0mmol/L.