Objective：To investigate the efficacy of amiodarone on ventricular fibrillation(VF)after release of aortic cross -clamp (ACC)in patients with left ventricular hypertrophy(LVH)undergoing cardiopulmonary bypass(CPB)surgery. Methods：In this study，a total of 54 patients with LVH were enrolled to receive CPB surgery in the First Affiliated Hospital of Nanjing Medical University from January 2021 to December 2021. All patients were randomly divided into either amiodarone group(group A)or control group(group C)， 27 cases in each group. Thirty minutes before ACC wasreleased，the trial drugs were administered intravenously. In group A，150 mg of amiodarone was pumped in 5 minutes. In group C，the same volume of normal saline was pumped in 5 minutes. Results：The incidence of VF in group A was lower than that in group C，and the duration of VF，the number of defibrillation and the defibrillation energy were lower than those in group C(P ＜ 0.05). The duration of temporary pacing in group A was longer than that in group C(P ＜ 0.05). After the end of CPB，the heart rate and mean arterial pressure were lower in group A，the mean pulmonary arterial pressure and the dose of vasoactive drugs was higher than those in group C(P ＜ 0.05). However，there was no significant difference in vasoactive drug dose and hemodynamic status between the two groups before the end of surgery(P ＞ 0.05). Conclusion：In patients with LVH undergoing CPB surgery，amiodarone can be safely used and reduce the incidence of VF，VF duration，defibrillation frequency and defibrillation energy after ACC was released.