Objective To study the effects and mechanism of different administrations of atorvastatin on myocardial ischemia/reperfusion (MI/R) in rats.Methods A total of 160 male SD rats were randomly divided into five groups:sham group,MI/R group,atorvastatin of conventional dose (MI/R + N) group,atorvastatin of preoperative signal loading dose (MI/R+SL) group,and atorvastatin of preoperative continuous loading dose (MI/ R+ML) group.MI/R model was established in the rats.Myocardial infarction size was detected by Evans blue/ TTC staining.The activity of ATPase of cardiac muscle and the levels of serum IL-6 and TNF-α were detected by ELISA.The level of LVEF％ was detected by small animal ultrasound.Results Compared with MI/R+N group,MI/R+ SL and MI/R+ ML groups had significantly smaller myocardial infarction size (P＜0.05),higher activity of ATPase (P＜0.05),lower levels of serum IL-6 andTNF-α (P＜0.05),and more advancedLVEF％ (P＜0.05).However,MI/R+SL group and MI/R+ML group did not differ significantly in the above-mentioned parameters.Conclusion Atorvastatin of loading dose might alleviate MI/R injury by improving ATP metabolism of cardiac muscle and reducing abnormal expressions of inflammation factors.Meanwhile,the administration of preoperative continuous loading dose and preoperative signal loading dose of atorvastatin may not differ in protecting against MI/R injury.