Aim To investigate the effects of curcumin post-treatment on oxidative stress injury induced by myocardial ischemia/reperfusion （I/R） and its mechanism. Methods Forty-eight male SD rats were randomized into four groups: sham group, I/R group, curcumin post-treatment group and curcumin+Zinc protoporphrinⅨ （ZnPPⅨ） post-treatment group. Myocardial I/R was carried out by ligation of left anterior descending coronary artery for 30 min followed by reperfusion for 6 h, and injection of curcumin or ZnPPⅨ before reperfusion via sublingual vein. Blood was collected at the end of reperfusion for detecting changes of myocardial pathologic changes, cardiac function, serum lactate dehydrogenase （LDH）, superoxide dismutase （SOD） and malondialdehyde （MDA）. Heme oxygenase-1 （HO-1） activity and expression in myocardial tissue was detected by HO-1 activity detection kit and Western blot. Results Compared with I/R group, post-treatment with curcumin resulted in an enhanced activity and expression of HO-1 protein, and reduced oxidative stress injury induced by I/R （P<0.05）. This protective effect was considerably attenuated by ZnPPⅨ （an inhibitor of HO-1）.