Abstract: AIM To observe and analyze echocardiogram( ECG) characteristics and associated factors between acute coronary syndrome( ACS) patients with and without type 2 diabetes mellitus( T2DM). METHODS We analyed 300 patients with ACS in our hospital from June to November 2012. Patients were divided into two groups: T2 DM group and non-T2 DM group. General data,blood test results,ECG parameters and GRACE risk scores were compared between groups. RESULTS The rates of females,blood glucose at admission,fasting blood glucose( FBG),triglyceride and GRACE risk scores were higher in the T2 DM group( P < 0. 05 or P < 0. 01). ECG results revealed that left ventricular ejection fraction( LVEF),stroke volume,and left ventricular fractional shortening were significantly lower,and left ventricular end systolic diameter and left ventricular end systolic volume were higher in the T2 DM group group( P < 0. 01). Morever,more patients had mild damage of left ventricular systolic function( LVEF45%- 54%; P < 0. 05). LVEF in the T2 DM group was negatively correlated with FBG,creatinine and GRACE risk scores,whereas it was negatively correlated with blood glucose at admission,and creatinine and GRACE risk scores in the non-T2 DM group( P < 0. 05 or P < 0. 01). Multiple linear regression analysis showed that FBG,body mass index and sex independently predicted left ventricular systolic dysfunction and the standardized regression coefficient of FPG was greatest(- 0. 312). CONCLUSION Left ventricular systolic dysfunction occurs earlier in ACS patients with T2 DM and is closely related to the higher level of FBG.