Abstract: OBJECTIVE To evaluate the intervention effect of Sibiraea angustata volatile oil on pituitrin-induced acute myocardial ischemic injury in mice. METHODS The acute myocardial ischemic injury model was made by injecting pituitrin in mice and treated with Sibiraea angustata volatile oil, the change of the J spot was measured by electrocardiogram, the biochemical indicatorsCatalase(CAT), Glutathione transferase(GSH-Px), superoxide dismutase(SOD) and lactic acid(LD) in surum were measured and compared; The heart were fixed for pathological investigation to observe the degree of myocardial ischemic injury and myocardial infarct size by optical microscope, the activity and mRNA expression of caspase-3 was measured by RT-PCR. RESULTS Compared with the model group, the moving up of J spots in the treated groups was significantly inhibited(P<0.05), the activities of SOD, GSH-Px and CAT were increased(P < 0.05 or P < 0.01), while the content of LD was decreased(P<0.05); Moreover, the histopathological research indicated Sibiraea angustata volatile oil significantly diminished the areas of cardiac muscles injured by ischemia. Mechanisms studies indicated that the mRNA expression of caspase-3 was decreased significantly(P<0.05). CONCLUSION Sibiraea angustata volatile oil has protective effect on acute myocardial ischemic injury in mice and related to the caspase-3 downregulation.