Abstract: This paper discusses the preparation method of improving rat myocardial infarction model.Aftcr anaesthesia and oral trachea cannula,animal model was produced by ligation of the left anterior descending through left thoracotomy.Through carotid artery injecting Evans blue and taking out the heart,we can observe the heart share and infarction area after 28 days.The success rate of myocardial infarction model is 87.5,the survival rate is 90.28 days after surgey the left ventricle become large,the left ventricular wall of infarction area is thin,the color is white.This research provides a simple,easy,detailed method of making the myocardial infarction model by the experiment,for beginners reference.