Abstract: The effects of praeruptorin C (Pra-C, 15 mg/kg, bid×3d, ip) on global myocar-dial ischemia and reperfusion were investigated in the isolated working rat hearts. The results at 35min after reperfusion showed that as compared with the values before ischemia, AP, LVSP, +dP/dt_max, --dP/dt_max,LVEDP and T were recovered up to 80±19%, 82±16%, 78±21%, 85±11%, 136±77% and 133±21%, respectively. The correspording parameters of Nifedipine (Nif,60 μg/kg, bid×3 d,ip) were 80±16%,97±30%,102±24%,106±32%,129±41% and 145±46%,respectively. The CF,SV and HR were recovered by 81±11%,104±20% and 78±7%when using Pra-C and 86±11%, 106±25% and 82±11%, respectively, when using Nif. Add-itionally ,in comparison of Pra-C and Nif with the ischemia group,the levels of creatine kinase releasedfrom cardiac cells decreased by 30% and 40%;while calcium accumulation in myocardial mitochondri-a were 41% and 46% ,respectively. The study suggests that the protective effects of Pra-Con myocar-dial cells in the isolated working rat heart during myocardial ischemia are similar to those Nif.