Objective To analyze the changes of Tpeak-Tend interval (Tp-Te) in patients with type 2 diabetes mellitus (T2DM),and to explore the relationship between the changes of Tp-Te and ventricular arrhythmias. Methods A total of 112 patients with T2DM were selected from the Department of endocrinology of our hospital from June 2014 to May 2016 (T2DM group),and 65 subjects underwent healthy physical examination in our hospital were selected as the normal control group (NC group) during the same period.The general data,fasting plasma glucose (FPG),glycosylated hemoglobin (HbA1c),Tp-Te,Tp-Te dispersion (Tp-Ted) were compared between the two groups.The changes of Tp-Te in patients with or without ventricular arrhythmia in T2DM group were also analyzed. Results The FPG,HbA1c,LDL-C,TC and heart rate were significantly higher in T2DM group than in the NC group (P<0.05).Compared with the control group,V5 lead Tp-Te and Tp-Ted in T2DM group was significantly prolonged (P<0.05).IN T2DM group,V5 lead Tp-Te and Tp-Ted were significantly longer in patients with ventricular arrhythmias than in patients without ventricular arrhythmia (P<0.05).Multiple logistic regression analysis showed that the increase of HbA1c and FPG were independent risk factors for prolonged Tp-Ted,and Tp-Ted was an independent risk factor for ventricular arrhythmia. Conclusion Patients with T2DM are more likely to have prolonged Tp-Ted.The prolonged Tp-Te and Tp-Ted could increase the incidence of ventricular arrhythmias.