Objective：To study the change of plasma lipoprotein-associated phospholipase A2（Lp-PLA2）concentration in patients with acute myocardial infarction（AMI）and its correlation with cardiac function after AMI. Methods：Ninety consecutive AMI patients who met the study criteria were enrolled. The plasma Lp-PLA2 levels were measured immediately after admission（T0），the next day（T1），the third day（T2），and the seventh day（T3），N-terminal pro brain natriuretic peptide（NT-proBNP）was measured one month after AMI（T4），left ventricular ejection fraction（LVEF）was measured by two-dimensional echocardiography at T1 and T4. Pearson correlation analysis was used to analyze the correlation between Lp-PLA2 and LVEF or NT-proBNP. In addition，48 healthy volunteers and 43 stable angina pectoris patients were enrolled as the controls. Results：The level of plasma Lp-PLA2 showed dynamic changes after AMI，it was increased significantly after the onset of the disease，but decreased to normal level after 7th days of admission［（61.42±36.99）mg/L vs.（49.83±27.17）mg/L，P > 0.05］. The correlation analysis showed that there was no significant correlation between on-admission plasma Lp-PLA2 and C-reactive protein level（r=0.06，P > 0.05）or between Lp-PLA2 and cardiac troponin T level（r=-0.07，P > 0.05）. Further studies showed that there was no significant correlation between plasma Lp-PLA2 level at T0 and plasma NT-proBNP level at T4（r=0.16，P > 0.05）or LVEF at T4（r=-0.09，P > 0.05）or the difference of LVEF between T1 and T4（r=0.04，P > 0.05）. Conclusion：The plasma level of Lp-PLA2 showed dynamic changes after AMI，which reflected the unstable state of artery plaques，but it was not related to the recovery of cardiac function after AMI.