Abstract: 【ABSTRACT】Objective: To explore the prediction function on cardiac function of plasma B type natriuretic peptide in acute myocardial infarction.Methods:Select 77 cases of acute myocardial infarction in our hospital,record the name,sex,age,smoking and drinking history,basic diseases,Killip classification of cardiac function of the patients,measure the plasma BNP level,and measure the left ventricular ejection fraction (LVEF) by the cardiac ultrasound in 24 hours. After 3 months of follow-up,detect the concentration of BNP and do the cardiac ultrasound again,record the cases of death. Results:The patients were divided into 4 groups according to Killip classification of acute myocardial infarction, the BNP levels gradually increased and the difference is significant (P＜0.05).The BNP level and Killip classification has positive correlation(r=0.937,P＜0.01).The BNP level and LVEF has negative correlation(r=-0.916,P＜0.01).10 patients died during the observation period,the BNP level and Killip classification in the acute phase of death group were Significantly higher than that of the survival group.The LVEF of death group were Significantly lower than that of the survival group(P＜0.01). Conclusion:The BNP has a good prediction function on cardiac function in acute myocardial infarction.