Abstract: Objective To investigate the changes and differences of arrhythmia and residual shunt arising from interventional treatment in children with congenital perimembranous ventricular septal defect (PMVSD) using homemade and imported occluder devices. Methods Between January 2003 and June 2008, 396 PMVSD children were successfully treated with occluder devices in our hospital, comprising 186 with imported products and 210 with homemade ones. Close observation on ECG was made during the procedures and was sustained as a routine until 3 to 7 days after treatment, or 1 to 2 weeks if indicated, to identify the changes in each ECG lead. Incidences of arrhythmia and residual shunt in both groups were recorded and clinical outcome of children with severe arrhythmia was evaluated. Results Arrhythmia and residual shunt were observed more in bulging-type than in other types of PMVSD (48.8% vs 29.1%, X~2=5.21, P<0.05; 12.5% vs 0.9%, X~2=23.31, P<0.01), as were more likely to occur after use of imported devices (68.2% vs 28.0%, X~2=14.18, P<0.01; 36.4% vs 1.2%, X~2=40.44, P<0.01). Imported devices resulted in more arrhythmia and residual shunt than did homemade products after treatment of bulging-type PMVSD (68.2% vs 41.4%, X~2=4.60, P<0.01 ; 36.4% vs 3.4%, X~2=15.60, P<0.01), but such an observation was not significant when the both were used for other types of PMVSD. Homemade devices were not found to induce more cases of arrhythmia and residual shunt than other types of PMVSD. The complete or recurrent third-degree atrioventricular block ( Ⅲ°AVB) occurred in 3 cases of each group using homemade or imported devices. Among them, one was with usual PMVSD and the other 5 were with bulging- type PMVSD. Conclusions While arrhythmia and residual shunt can be observed with treatment of PMVSD using either homemade or imported occluder devices, homemade products may result in lower incidence in bulging-type VSD than do imported devices. Close monitoring of ECG during and after treatment should be mandatory.