Transcatheter atrioventricular (AV) junction ablation with radiofrequency energy was performed in five patients with AV nodal reentrant tachycardia. Disappearance of ventriculoa-trial condcution in all patients was showed and no dual pathway was observed in four patients, in whom three patients occurred first degree AV block after ablation. No tachycardia was showed in all patients in the electrophysiology test and in follow-up of 1. 5-12. 5 months. The results sug-gested that the application of radiofrequency energy may be a suitable and safe therapeutic mothed for modification of AV nodal conduction in patients with AV nodal reentrant tachycardia.