Objective To investigate the effects of uncoupling protein 2 (UCP2) on the myocardial cells of mice with type 2 diabetes mellitus combined with hyperuricemia (HUA), and clarify the mechanism thereof. Methods The mouse cardiac myocytes (MCM) cultured with 25mmol/L high glucose (HG) medium were divided into two groups: HG plus 300μmol/L sodium palmitate for 18 hours as high glucose and high fat (HG+HF) group, and HG+HF plus 1500μmol/L uric acid (UA) for 18 hours as HG+HF+HUA group. Then the myocardial cells in HG+HF+HUA group, by use or not use UCP2 inhibitor genipin, were further divided into two groups: vehicle group and genipin group. In order to verify the mechanism of UCP2 in myocardial cells injury caused by high glucose, high lipid and high uric acid, the myocardial cells were divided again into genipin group and genipin+N-acetylcysteine (NAC) group. Accordingly, the apoptosis of myocardial cells were measured by flow cytometry at specific time, the mRNA and protein expressions of UCP2 were determined by q-PCR and Western blotting, and the levels of reactive oxygen species (ROS) were detected by DHE staining and ELISA. Results The apoptosis rate of myocardial cells increased obviously, and the expression levels of UCP2 decreased and of ROS elevated significantly in HG+HF+HUA group than in HG+HF group (P<0.05). As the expression levels of UCP2 decreased by genipin intervention, the apoptosis rate of myocardial cells and ROS level in HG+HF+HUA group increased more obviously (P<0.05). In contrast, such an effect was reversed by the application of antioxidants NAC (P<0.05). Conclusion UCP2 can inhibit oxidative stress and alleviate the apoptosis of myocardial cells induced by high glucose, high fat and high uric acid.