【Abstract】 Objective To observe the changes of left ventricular morphology and function in patients with prediabetes and diabetes mellitus by echocardiography.Methods 30 patients with prediabetes and 32 patients with type 2 diabetes mellitus were selected, 31 healthy people were as control group.All patients eliminated hypertension, coronary heart disease. Echocardiographic indexes were observed and analyzed statistically.Results There were significant differences in LAVI, IVS, LVPW, s" mean, e "mean", e "mean" and E/e "mean in type 2 diabetes group compared with the normal control group(P<0.01)；There were statistical differences in LAVI, IVS, s" mean, e "mean, E/e" mean in the prediabetic group compared with the normal control group(P<0.05).There was no significant difference in LVEDD and a’ mean in diabetic and prediabetic group. Conclusion Compared with the control group, there was significant difference in left atrial morphology and left ventricular function in the patients with prediabetes and type 2 diabetes mellitus.Echocardiography should be emphasized in patients with prediabetes.