Objective To investigate the effects of miR-182 mimics on cardiac function in type 1 diabetic mice and explore the mechanisms of action.Methods Forty 8-week-old C57 mice were randomly divided into 4 groups: control group (n=5), miR-182 mimics control groups group (n=5), type 1 diabetes group (n=15) and type 1 diabetes treated by miR-182 mimics (n=15). Eight weeks after modeling, the cardiac function was evaluated by a high-resolution ultrasonic imaging system for small animals (Vevo 2100). The samples of cardiac tissue was used to observe the ultrastructural changes by electron microscopy and to detect the expression levels of β-MHC, α-MHC, ANP, Col Ⅰ, Col Ⅲ and miR-182 mRNA.Results ① MiR-182 mimics improved the cadiac function of type 1 diabetic mice with an increase of left ventricular function and left ventricular short axis fractional shortening (P<0.01);② MiR-182 mimics significantly decreased the expression level of ANP, Col Ⅰ, Col Ⅲ protein and the ratio of β/α-MHC in cardiac tissue;③MiR-182 mimics induced ultrastructural changes of cardiac tissue in type 1 diabetic mice and the phenomenon of autophagy.Conclusions MiR-182 mimics may improve the cardiac function of type 1 diabetic mice, which is associated with decreased expression of hypertrophy-related gene ANP,β/α-MHC ratio and expression of Col Ⅰ, Col Ⅲ, reduction of mitochondrial damage and autophagy.