Abstract： Catheter ablation is an important therapy for atrial fibrillation (AF) in the last decade.In parallel,atrial tachycardia (AT) has become the most common type of arrhythmia after AF ablation,especially after extensive left atrial (LA) substrate modification.[1] The occurrence of AT after AF is due to the conduction gaps of ablation lines and the conduction obstacle caused by the ablation lesions.[2] Most of these ATs locate in LA,and here,we described a biatrial macroreentry AT (MAT) after AF ablation.