Abstract: ACG,ECG,PCG,CAG and IPG in 36 cases of acute myocardial infarction （AMI） in various stages were made to observe the changes in the left ventricular function.Twenty-four indexes in six stages of the disease,such as the 1st-3rd day,the 4th-7th day,the 2nd week,the 3rd week,the 4th week and the 5th week were analysed. 1.In all these 6 stages,as the results analysed by F test,the difference of LVET was of significance （p＜0.05）. 2.Daynamic analysis of each index in different stages （t test） showed differences of LVET,PEP/LVET,EF,QS₂,W₂,W₂/VOMO ＆ SV with statistical significance （p＜0.05—0.01）.Dynamic curves of these indexes in different stages including Sarnoff cardiac functional curves and left ventricular wall stress curves were made.It was indicated that the bigger the angles between the curves and the horizontal axises the better the function is and the angles enlarged with the course and stages of the disease.As a result of these studies we concluded that dynamic analysis of noninvasive left ventricular function tests in AMI in various stages may be used to estimate the changes of cardiac function accurately in evaluating patient’s condition,arranging the scheme of treatment,predicting the prognosis and guiding the rehabilitation.