Objective To evaluate the structure and function of left ventricle in diabetes mellitus (DM) patients without complications by myocardial velocity gradient (MVG) measured by myocardial velocity profile (MVP). Methods Thirty type 2 DM patients without complications and 30 healthy volunteers as controls were enrolled. The heart structure, systolic function and diastolic function of left ventricle were measured by echocardiography and the left ventricular mass index (LVMI) was calculated. Mitral annular systolic movement (Sm) , early rapid filling phase movement ( Em) and atrial contraction movement(Am) were measured by tissue Doppler image and the left ventricular MVG at diastole and systole in subendocardium and subepicardium (MVGs,MVGd) were measured by MVP. Results The diameter of left atria and left ventricle, thickness of interventricular septum and LVMI were higher in DM group than those of control group ( P <0. 05 or P <0. 01) , MVGs, MVGd, and Em were lower in DM group than those of control group( P <0. 05 or P <0. 01). There were no significant differences on E/A, Em/Am and E/Em between two groups. In addition, there were also no significant differences on Sm,left ventricular ejection fraction and left ventricular fraction shortening between two groups. Conclusions Structure and function of left ventricle have changed in patients of DM without complications. MVG measured by MVP is an accurate and sensitive index to assess left ventricular systolic and diastolic function.