Abstract: Objective To investigate the influence of linagliptin on the blood glucose change in patients with type 2 diabetes mellitus (T2DM)and to evaluate its safety.Methods A total of 98 patients diagnosed with T2DM admitted in our hospital were randomly divided into treatment group and control group,49 cases for each.Control group was treated with insulin glargine concomitant with dimethyldiguanide,on which basis treatment group was added with 5 mg /d linagliptin.Fast-ing plasma glucose (FPG),plasma glucose 2 h after meals (2hPG),glycosylated hemoglobin (HbAlc),body mass index (BMI)and adverse response rate before and 12 weeks after treatment were compared between two groups.Results After 12 weeks treatment,FPG,2hPG and HbAlc reduced evidently than treatment before,and were more lower in treatment group than in control group (P <0.05),while BMI had no significant difference before and after treatment in both groups (P > 0.05 ).The main adverse responses included nasopharyngitis,hypoglycemia, headache,gastrointestinal reactions and upper respiratory infection,in which only upper respiratory infection rate was significantly different between two groups (P <0.05).Conclusion linagliptin plus insulin glargine concomitant with dimethyldiguanide can effectively control blood glucose changes in patients with T2DM,which deserves to be widely used in clinic.