Abstract: ip DSPM 5 mg/kg 1 or 4 h before excision of the heart was found to preyent damage to the heart due to global myocardial ischemia. Compared with the controls, the heart rate, coronary resistance, contractile force and edema of the heart were all greatly improved during the 60 min reflow after 25 min of no-flow, especialy the heart pretreated with DSPM 4 h prior to excision. In addition, DSPM 1.5, 6 mg/kg markedly reduced the myocardial Ca²⁺ content measured by isoproterenol in mice. DSPM at higher dosage also lowered the normal myocardial Ca²⁺ content. These results suggest that DSPM may have a protective effect on myocardial ischemia which might be associated with its calcium antagonistic action.