Abstract: AIM:To explore the contributions of insulin and metformin to sympathetic neural remodeling after myocardial infarction in rats with type 2 diabetes. METHODS: Samples were obtained from periinfarcted areas, ventricular septum and right ventricle in infarcted diabetic rats. Using immunohistochemistry and computer image processing technique, the expressions of sympathetic nerve were examined in the control group, insulin group and metformin group, respectively. RESULTS: In insulin group, densities of sympathetic nerve in three areas were higher than in control group (P<005) and densities were lower in metformin group compared with those in control group (P<005). CONCLUSION: Contrary to metformin, insulin aggravates sympathetic neural regeneration and remodeling after myocardial infarction in rats with type 2 diabetes.