Objective To observe protective effect of pinacidil combined nitroglycerin on myocardial ischemiareperfusion in rabbits．Methods 50 rabbits were randomly divided into SO, I/R, NG, PN and PN+NG group,30 min before ischemia intravenous pinacidil 250ug/kg, respectively. The venous blood was taken at reperfusion 0 (T0), 30 (T30), 60 (T60), 120 (T120) minutes to detect MDA, hydroxylamine assay superoxide dismutase (SOD), nitric oxide (NO). The activity of CK was detected with chemocolorimotry method. The left anterior descending artery was recorded at the end of reperfusion. Each myocardial slice was stained using Evans blue and Triphenylte trazolium chloride, and then was quantified for area at risk (AAR) and Left Ventricular area using (Image-Pro Plus, Media Cybernetics).Results SOD of Shamoperation, nitroglycerin group, pinacidil group and nitroglycerin + pinacidil group was higher than that of ischemiareperfusion group(P＜0．01&P＜0.05). SOD of nitroglycerin + pinacidil group was higher than that of nitroglycerin group and pinacidil group(P＜0.01). MDA of Shamoperation,nitroglycerin group, pinacidil group and nitroglycerin + pinacidil group were lower than that of ischemiareperfusion group (P＜0．01&P＜0.05). MDA of nitroglycerin + pinacidil group was lower than that of ischemiareperfusion group (P＜0.01). NO of Shamoperation,nitroglycerin group, pinacidil group and nitroglycerin + pinacidil group was higher than that of ischemiareperfusion group (P＜0．01). NO of nitroglycerin + pinacidil group was higher than that of nitroglycerin group and pinacidil group (P＜0．01). LVSP in ischemiareperfusion, nitroglycerin, pinacidil,nitroglycerin+pinacidil groups significantly decreased compared with that in Sham-operation group (＜0.01). At T150, compared with nitroglycerin, nitroglycerin+pinacidil groups, the cardiac function indexes in ischemiareperfusion group significantly decreased(P＜0.05). The cardiac function indexes of nitroglycerin and pinacidil group were decreased than that of nitroglycerin+pinacidil group (P＜0.01). The activity of CK in nitroglycerin, pinacidil, nitroglycerin+pinacidil, ischemiareperfusion groups more significantly increased than that Shamoperation group (P＜0.01/ P＜0.05). Compared with ischemiareperfusion group, the size of myocardial infarct in nitroglycerin, pinacidil, nitroglycerin+pinacidil groups significantly reduced.Conclusion Nitroglycerin and pinacidil have obvious antirabbit myocardial ischemiareperfusion pharmacological preconditioning in myocardial protection.