This study aims to explore the protective effect of pterostilbene (PTE) on myocardial ischemia-reperfusion injury in mice based on liver kinase B1/adenylate-activated protein kinase(LKB1/AMPK) signaling pathway.Sixty male Kunming mice were selected for the study and randomly divided into sham-operated (Sham) group,model (Mod) group,low-dose PTE (PTE-L),medium-dose PTE (PTE-M),and high-dose PTE(PTE-H) groups,and aspirin (ASP) group.Myocardial histopathological changes,cardiomyocyte apoptosis,cardiac function indexes,myocardial enzyme indexes,oxidative stress indexes,and LKB1/AMPK signaling pathway related protein and mRNA expression were observed in each group;The results showed that PTE improved myocardial histopathological changes;Compared with Sham group,the apoptosis rate of cardiomyocytes,left ventricular end-systolic internal diameter (LVESD),left ventricular end-systolic internal diameter (LVEDD),infarction area,myocardial enzyme index level,malondialdehyde (MDA) content in other groups were higher;left ventricular fractional shortening (LVFS),left ventricular ejection fraction (LVEF),content of superoxide dismutase enzyme (SOD) in myocardial tissue,and LKB1/AMPK signaling pathway-related proteins and mRNA expression in other groups were lower.Compared with Mod group,the apoptosis rate,LVESD,LVEDD,infarction area,myocardial enzyme index level,and MDA content in myocardial tissue in PTE and ASP groups were lower;LVFS,LVEF,SOD content in myocardial tissue,LKB1/AMPK signaling pathway-related proteins and mRNA expression in PTE and ASP groups were higher (P＜0.05);Among them,the results were optimal in the PTE-H and ASP groups,and the difference between the two groups was not statistically significant (P > 0.05).It suggests that PTE can effectively improve myocardial ischemia/reperfusion,inhibit cardiomyocyte apoptosis and improve myocardial infarction in mice,and its mechanism is related to LKB1/AMPK signaling pathway.