【Abstract】Objective To explore the left ventricular function of younger type 2 diabetes mellitus (T2DM) patients by echocardiography. Methods 73 patients with T2DM were enrolled in the study. According to glycated hemoglobin (HbA1c) control level, the patients were divided into T2DM group (HbAlC＜7%, n=40) and T2DM group (HbAlC≥7%, n=33). 35 matched volunteers were chosen as control group. Two dimensional echocardiography was used to measure the size of cardiac chamber and left ventricular ejection fraction (LVEF). The mitral valve blood flow peak early diastolic velocity (E), peak later diastolic velocity (A), anterior mitral annulus diastolic peak velocity (e’), E/A, E/e’ and Tei index measured by the pulsed wave Doppler and tissue Doppler imaging (TDI). Two dimensional speckle tracking imaging (2DSTI) was used to analyze the global longitudinal systolic strain (GLS) of left ventricle. Results There were no statistical differences in the E/A and LVEF among three groups（P＞0.05）. The E/e’ was statistical difference in the control and T2DMⅠ group (P＜0.01), T2DMⅠand T2DMⅡgroup (P＜0.05). The GLS was decreased in T2DMⅡ group, and significant difference was found when comparing T2DMⅡ group with T2DMⅠ group (P＜0.05). Tei index was increased in T2DMⅡ group, and there was statistical difference comparing with T2DMⅠ group (P＜0.05). Conclusion The new technical parameters E/e’, Tei index and GLS of echocardiography could reflect the reduction of subclinical left ventricular function in T2DM younger patients with poor blood glucose control in the early stage, and the left ventricular diastolic function impaired earlier than systolic function.