OBJECTIVE： To explore the effects of Metabolic index of exenatide on body mass index （BMI） of type 2 diabetes patients. METHODS： According to different BMI， 106 patients with type 2 diabetes were divided into normal group （35 cases）， overweight group （35 cases） and obesity group （36 cases）. Based on previous hypoglycemic therapy， 3 groups received exenatide. Blood pressure， body weight， BMI， blood glucose index， TG and ADR were compared among 3 groups. RESULTS： After treatment， blood pressure， body weight and BMI of overweight group and obesity group were significantly better than before， with statistical significance （P＜0.05）； fasting blood glucose， postprandial 2 h blood glucose， glycosylated hemoglobin， triglycerides of 3 group were significantly lower than before， with statistical significance （P＜0.05）. Changes of body weight and BMI in overweight group and obesity group were significantly higher than in normal group， with statistical significance （P＜0.05）. No serious complications was found in 3 groups. CONCLUSIONS： The therapy of exenatide is suitable for overweight and obese type 2 diabetic patients.