Abstract: AIM:To investigate the protective effect of post-treatment with curcumin on myocardial ischemia reperfusion in adult Sprague Dawley (SD) rats along with the underlying mechanism. METHODS: The hearts of 40 SD rats were isolated and subjected to Langendorff perfusion. Rats were randomized into five groups (n=8): control group, I/R group, I/R+Cur group, I/R+Cur+AG group and AG group. Myocardial injuries in rats were produced by ischemia for 60 min followed by 60 min reperfusion. HR, LVDP, +dp/dtmax, CF and DP were recorded, respectively, before and 15, 30, 45 and 60 min after reperfusion. Myocardial infarct sizes were observed by TTC test and JAK and STAT3 as well as active phosphorylated forms of JAK2 and STAT3 were detected by Western blotting. RESULTS: In I/R group, systolic and diastolic functions were significantly reduced. Myocardial infarct size was increased and the phosphorylated forms of the JAK2 and STAT3 were significantly higher compared with the control group (P<0.01). In I/R+Cur group, systolic and diastolic functions were improved, myocardial infarct size was significantly smaller, and the phosphorylated forms of JAK2 and STAT3 were significantly higher compared with those in the I/R group (P<0.01). All these parameters in the I/R+Cur+AG group were decreased significantly compared with I/R+Cur group (P<0.01). No significant difference was observed in hemodynamic and myocardial infarct size parameters between control group and AG group. CONCLUSION: Post-treatment with curcumin can significantly reduce myocardial ischemia/reperfusion injury partly via JAK2/STAT3 signaling pathway.