Abstract: AIM To investigate the role of Drp1-related mitophagy in cardiomyocytes exposed to high glucose (HG). METHODS Neonatal mouse ventricular myocytes were separated and cultured in DMEM with normal (5.5 mmol/L) doses of glucose for 48 hrs. Drp1 over-expression adenovirus was transfected into cardiomyocytes, After 24 hrs transfection, cardiomyocytes were cultured in DMEM with normal (5.5 mmol/L) or high doses (33 mmol/L) of glucose for 72 hrs. So we divided the experiment into four groups: ①NG+lacZ group; ②NG+Drp1 group; ③HG+LacZ group; ④HG+Drp group. Expressions of Drp1, Parkin, LC3 and P62 were analyzed by Western blot. The number of autophagosomes was measured by immunofluorescence, the mitochondrial membrane potential was measured by JC-1 staining and the apoptotic index was examined by TUNEL. RESULTS Compared with those in the control group, expressions of Parkin, LC3 and the number of autophagosomes were obviously decreased. The expressions of Drp1 and P62 were elevated significantly (P<0.05), the mitochondrial membrane potential was degraded (P<0.05) and the apoptosis index was increased significantly (P<0.05) when cardiomyocytes were exposed to HG. Compared with those in the HG group, LV-Drp1 up-regulated the expression of Parkin, LC3 and autophagosomes (P<0.05), enhanced the mitochondrial membrane potential(P<0.05) and reduced the apoptosis index (P<0.05) when cardiomyocytes were cultured with high glucose. CONCLUSION Drp1 improves the mitochondrial membrane potential and down-regulates the apoptosis index in cardiomyocytes exposed to high glucose via mitophagy.