Abstract: Objective To assess the protective effect of cariporide on isolated donor heart for transplantation in rats through Langendorff. Methods Forty-eight male Wistar rats were randomly divided into control group which was further divided into 8h and 12h histidine-tryptophan-ketoglurate（HTK） solution groups and experiment group which was further divided into 8h and 12h 20μmol/L cariporide+HTK groups.The isolated donor hearts removed from rats were perfused in Langendorff with their basic hemodynamic values assayed,and then preserved in cold cardiac muscle protective solutions at 4℃ for 8h and 12h,respectively.Their hemodynamic parameters and blood flow in coronary artery were detected after reperfusion.Water content,release of CK-MB from cardiac muscle,and APT level in cardiac cells were measured.Changes in ultra-microstructure of cardiac cells were observed. Results The mean left ventricular developed pressure（LVDP） and ATP level in cardiac muscle were significantly higher in experiment group than in control group 8h after ischemia induced by hypothermia（P＜0.05）.The release of CK-MB from cardiac muscle was decreased,but no significant difference was observed in it between the 2 groups.The mean LVDP was significantly higher,the release of CK-MB from cardiac muscle was significantly less,and the ATP level in cardiac muscle was significantly higher in cariporide group than in HTK group 12h after ischemia induced by hypothermia（（98.37±16.34）mmHg vs（43.21±14.33）mmHg,（4.373±1.489）IU/L vs（34.23±3.328）IU/L,（34.32±1.87）μg/g vs（17.92±1.47）μg/g,（P＜0.01））. Conclusion Cariporide can protect isolated donor rat hearts and prolong their cold preservation time.