Objective:To investigate the types and prognosis of ectopic arrhythmia(EA) after transcatheter closure of perimembranous ventricular septal defects(PMVSD)and the risk factors of EA. Methods:228 patients with PMVSD were accepted transcatheter closure successfully. Electrocardiogram(ECG) and Holter ambulatory electrocardiographic monitoring were underwent in all patients both pre-and post-procedure,as well as 1,3,6 months and every year after the procedure. Results:Sixty-one case-times of new EA(19.7%) were detected in 45 patients which included 25 case-times of accelerated idioventricular rhythm,14 case-times of accelerated idiojunctional rhythm,14 case-times of ventricular premature beat and 8 case-times of junctional escape rhythm. All the patients with EA had not been given special treatment,EA in 43(95.6%) cases sustained(4.16 ± 2.71) days,2 cases recovered sinus rhythm in the first month of follow-up,and new EA was not found during the follow-up. It was found that the risk factors of EA after closure were related to the distance from the lower margin of the defects to septal leaflet of the tricuspid valve(DDSTV) and the distance from upper margin of the defects to the ring of the right aortic valve(DDRAV). DDSTV ≤ 2.45 mm or DDRAV ≥ 3.05 mm has good predictive value of the incidence of EA. Conclusion:EA is a common complication after transcatheter closure of PMVSD,but with better prognosis in our study. We should closely monitor ECG changes and treat the patients with the risk factors after interventional treatment in time.