Abstract: Objective To study the ECG characteristics of frequent premature ventricular beat （PVB） originated from ventricular outflow tract （VOT） and their relation with coronary artery disease. Methods Twenty four–hour dynamic ECG of 111 senile patients with frequent PVB originated from VOT and characteristics of their QRS complex were retrospectively analyzed with the proportion of QRS complex calculated. Results Of the 111 senile patients with frequent PVB, 45, 41 and 25 were originated from VOT, non- VOT, and multiple sites, respectively. The incidence rate of coronary artery disease was significantly lower in patients with PVB originated from VOT than in patients with PVB originated from non-outflow tract. Conclusion The electrophysiological characteristics of male senile patients with PVB partially originated from VOT are different from those of general myocardial cells with a clear automaticity and an electrophysiological anisotropy. PVB originated from VOT is not related with myocardial ischemia.