Abstract： Objective To investigated the different effect of moderate-intensity continuous training (MCT) and high-intensity interval exercise training (HIT) on ventricular remodeling and mitochondrial homeostasis after acute myocardial infarction (AMI).Methods The AMI rat model was achieved by ligating coronary artery.The AMI and sham operation rats were randomly (random number) divided into four groups:sham operation group (Sham),AMI control group (AMI),AMI MCT group (AMI + M),and AMI HIT group (AMI + H).Animals in the AMI + M and AMI + H groups underwent 4 weeks MCT and HIT respectively.Five weeks after AMI,hemodynamic changes,mitochondrial bioenergetics,and PINK1,Beclinl,Mfn2,Drp1,Tfam,COXⅣ,PGC-1α were detected.Results Comparing with AMI group,in AMI + M and AMI + H groups,Beclin1,PINK1,Mfn2 and PGC-1α expression elevated significantly (P ＜0.05 or P ＜0.01),whereas ROS generation and Drp1 expression showed dramatic decrease (P ＜ 0.05 or P＜0.01).In addition,in AMI + H group,±dp/dt max,mitochondrial membrane potential,ATP synthesis activity,Tfam and COXⅣ expression improved significantly (P ＜ 0.05).Comparing with AMI + M group,in AMI + H group,± dp/dt max,PGC-1α,Tfam and COX Ⅳ expression improved significantly (P ＜ 0.05).Conclusions HIT is superior to MCT for ameliorating ventricular remodeling and mitochondrial homeostasis after AMI.