Abstract： Objective To investigate the characteristics of heart structure and function in patients with type 2 diabetes mellitus (T2DM ) and analyze the influencing factors . Methods A total of 486 patients with T2DM and 140 healthy controls were enrolled in this study .The results of echocardiography were compared between the two groups .The influencing factors of heart structure and function in patients with T2DM were analyzed . The T2DM patients were then divided into four subgroups according to diabetes duration .The heart structure and function were compared among the subgroups . Results (1) Interventricular septal thickness (IVSTd) ,left ventricular posterior wall thickness (LPWTd) ,left atrial dimension(LAD) ,and pulmonary arterial diameter (PA )were increased in T2DM group than in control group(P<0.05);Left ventricular diameter (LVIDd) ,right ventricular diameter (RVIDd) ,and right atrial area(RA-A ) were not significant difference between the two groups . E peak ,E/A value and ejection fraction (LVEF) decreased ,A peak increased significantly in T2DM group than in control group (P<0.05) .(2) There was no significant change in heart structure among subgroups with different diabetes duration .E/A value was lower in 5～10 years subgroup than ≤5 years subgroup .The E/A value and LVEF were lower in≥15 years subgroup than ≤5 years group .(3) IVSTd and LPWTd were significantly correlated with sex ,body mass index (BMI) ,diabetes duration ,C-reactive protein (C-RP) ,intima-media thickness(CIM T ) ,high density lipoprotein (HDL-C ) ,and LVEF .LAD was significantly correlated with age ,BMI ,diabetes duration ,NT-proBNP ,HOMA-IR (C-P) ,HDL-C and LVEF .There was no correlation between LAD and FPG ,HbA1 c ,TG ,and SUA .The diabetes duration was a risk factor for thickening of LPWTd .BMI was a risk factor for LAD .A peak ,E peak and E/A value in patients with T2DM were significantly correlated with age and diabetes duration .LVEF was correlated with NT-proBNP .Age is a risk factor for A peak ,E peak and E/A value . Conclusion The changes of heart structure in T2DM patients mainly manifested in the left ventricular hypertrophy ,the enlargement of the left atrium and pulmonary artery .There is no significant heart structure change with the progression of diabetes .The changes of heart function in T2DM patients mainly manifested the contraction and diastolic dysfunction , and with the progression of diabetes ,the worsening of diastolic function was more significant .