Objective To determine the effect of crocin regulating miR-139-5p/ATF4 axis on myo-cardial injury and energy metabolism in rats with CHF.Methods A total of 84 male SPF SD rats were randomly divided into sham operation group,model group,crocin low-,medium-and high-dose groups,captopril group and crocin+miR-139-5p inhibitor group,with 12 in each group.Car-diac function indexes,myocardial histomathological morphology,apoptotic rate,myocardial injury indexes,heart failure indexes,inflammatory indexes,oxidative stress indexes,myocardial ATP content,SDH activity,and miR-139-5p and ATF4 mRNA expression levels were detected in rats.The targeting relationship between miR-139-5p and ATF4 was verified.Results Compared with the conditions in the model group,crocin treatment at different doses reduced apoptotic rate of cardiomyocytes,decreased MDA content,LVEDD and LVESD values and cTnI,cTnT,CK-MB,NT-proBNP,TNF-α and IL-1β levels,and declined ATF4 mRNA level,and increased LVEF and LVFS values,SOD activity,ATP content,SDH activity and miR-139-5p level(P＜0.05).Com-pared with the crocin high-dose group,the crocin+miR-139-5p inhibitor group had higher apop-totic rate of cardiomyocytes[(22.68±3.25)％vs(11.94±1.38)％,P＜0.05],increased LVEDD and LVESD value,raised MAD content and cTnI,cTnT,CK-MB,NT-proBNP,TNF-α and IL-1βlevel,and elecated ATF4 mRNA level,and decreased LVEF and LVFS value,SOD activity,ATP content,SDH activity and miR-139-5p level(P＜0.05).There was a targeting relationship be-tween miR-139-5p and ATF4.Conclusion Crocin can improve myocardial injury and energy me-tabolism in CHF rats,which may be related to its regulation of miR-139-5p/ATF4 axis.