Object:To observe the effect of Hongjingtian Injectio on myocardial ischemia and cardiac infarction in anesthetized dog.Methods: Epicardial electrography was used to measure the extent and range of myocardial ischemia

quantitative histological method（N-BT staining）was used to determine the range of cardiac infarction

and changes of related indexes during myocardial ischemia and cardiac infarction were compared.Results:Hongjingtian Injectio can remarkably reduce the extent（∑-ST）and the range（N-ST） of myocardial ischemia

and can reduce the size of infarction area exhibited by N-BT staining

It can effectively inhibit increasing activity of serum creatine kinase（CK）and release of lactate dehydrogenase（LDH）

reduce level of serum endothelin（ET）and thromboxane B

2

（TXB

2

）

increase content of 6-keto-PGF

1α

and the ratio of 6-keto-PGF

1α

to TXB

2

.Conclusion:The effect of Hongjingtian Injectio in improving acute myocardial ischemia and cardiac infarction in anethetized dog is similar to Hexinshuang Injectio

（positive contrast agent）.