AIM:To explore the protective effects of the Flos lonicerae compound preparation(FLCP) on acute myocardial ischemia induced by Pituitrin in rats.Methods:rats were randomly divided into the normal control,model,the dosage of FLCP13.50 g/kg,the dosage ofFLCP27.0 g/kg and Di Ao five groups by screening,ten rats of each group.Anamals were treated intragastrically with the dosage of FLCP13.50g/kg,the dosage of FLCP27.0 g/kg and Di Ao aqueous once daily for 20 days respectively,except the others were treated intragastrically with distilled water in normal and model groups.After 45 minutes of administration,the changes of ECG lead H were recorded after injection of 15s and 45s,at the same time,the activity of LDH,SOD,SDH and the content of MDA,NO in serum were detected,meanwhile the activity of SOD,SDH and the content of MDA,NO in heart tissue were assayed by colorimetric method.Results:As compared with the model group,FLCP have a significantly role with the changes of T wave,and the activity of LDH in serum was significantly decreased,meanwhile the activities of SOD and SDH and the content of NO in serum and tissue were increased ;and the contents of MDA in serum and tissue were significantly decreased,and FLCP is stronger than Di Ao Xin Xue Kang in increasing the activities of SOD and decreasing the contents of MDA in heart tissue.Conclusion:FLCP have a markedly protective action on acute myocardial ischemia induced by Pituitrin.