OBJECTIVE： To comparison the clinical efficacy and safety of sitagliptin and Repaglinide in the treatment of newly diagnosed patients with type 2 diabetes mellitus. METHODS： 214 newly diagnosed patients with type 2 diabetes mellitus were randomly divided into study group and control group with 107 cases in each group according to random number table method. Both group received routine diabetes diet， health education and suitable exercise. Control group was treated with Repaglinide tablet 1.0 mg， tid； while study group was treat with Sitagliptin tablet 100 mg， qd. Lab indexes， FBG， PBG， HbA1c and BMI were observed in 2 groups before and after treatment. ADR were compared between 2 groups. RESULTS： There was no statistical significance in lab indexes between 2 groups before and after treatment （P＞0.05）. After treatment， FBG， PBG， HbA1c were significantly decreased significantly in 2 groups， with statistical significance （P＜0.05）， there was no statistical significance between 2 groups （P＞0.05）. BMI of 2 groups were increased significantly， and the study group was higher than the contrd group， with statistical sighificance （P＜0.05）. Patients in the study group had no hypoglycemia， while 3 patients in the control group suffered from it， there was statistical significance （P＞0.05）. CONCLUSIONS： Sitagliptin is similar with repaglinide in therapeutic efficacy； both can effectively reduce blood glucose of elderly patients with newly diagnosed type 2 diabetes mellitus， and the incidence of hypoglycemia was low， the saterty was good， but sitagliptin has a better control of BMI in patients.