Abstract: Objective To evaluate the right heart functions in patients with type 2 diabetes mellitus(T2DM)by echocardiography,and to find out the correlation between echocardiographic findings and the severity of T2DM. Methods A total of 149 patients with T2DM were selected and divided into the non-diabetic microangiopathy group(70 cases,T2DM-Ⅰ)and the diabetic microangiopathy group(79 cases,T2DM-Ⅱ)according to the diagnostic criteria of T2DM.And 90 healthy age-matched volunteers were selected as controls.All subjects underwent echocardiography.The right ventricular size and function were compared among the three groups. Results Tricuspid orifice E/A of Two T2DM groups were lower than that of the control group (P＜0.01);Tricuspid E/E’ was significantly different between T2DM-Ⅰand the control group(P＜0.05),and it was significantly different between T2DM-Ⅱand the control group(P＜0.01)as well.There were also significant differences of RV-strain and Tei index in the T2DM-Ⅱ as compared with T2DM-Ⅰand the control group(P＜0.01).There were no significant differences in FAC and TAPSE among the three groups(P＞0.05).The indexes except RVWT between T2DM-Ⅱ and T2DM-Ⅰ were significant difference (P＜0.01).The right ventricular size and function were not significant difference(P＞0.05). Conclusion With the development of diabetes,the functional impairment of the right heart appears earlier than structural changes,and right ventricular diastolic function is early impaired than the systolic function.