Abstract: Flecainide is a relatively new Ic type of antiarrhythmic drug widely used in the control of ventricular tachyarrhythmia. Aim of the present study is an attempt to attest if the ventrucular fibrillation threshold （VFT） can be raised by flecainide. The mean VFT of left ventricle in the control was 29.77=4.5mA. The values were 9.58=1.42mA and 28.00=4.51mA during ischemia and reperfusion, respectively. After injection of flecainide the mean VFT in all the three steps increased strikingly （control: 44.54±2.08, ischemia: 38.25±4.34, reperfusion: 39.08+3.24,P＜0.05 or 0.01）. These results showed that flecainde can definitely raise the VFT in normal, reperfused and especially in ischemic canine myocardium. The decrease of CO showed the negative inotropic effect of flecainide.