【Objective】To explore the association between paced QRS duration（QRSd）and the occurrence of atrial fibrillation（AF）in the patients with permanent pacemaker.【Methods】We selected 180 consecutive patients underwent pacemaker implantation for complete/advanced atrioventricular block. All of patients were paced from the right ventricular septum. Electrocardiography recordings were obtained at the beginning and the end of pacemaker implantation. QRSd was measured in precordial leads（V1，V4 and V6），I lead and AVF lead. The change value of QRSd was calculated by subtracting the pre-implantation QRSd from the post-implantation QRSd.【Results】The occurrence of AF was observed in 64（35.56%）patients. No significant differences in pre-implantation QRSd were observed between the AF occurrence and non-occurrence groups. The change value of QRSd in leads V4（P=0.022），and V6（P=0.001）differed significantly between the occurrence and non-occurrence groups. Cox??s proportional hazard model suggested that change value of QRSd in lead V6（P=0.005，HR 1.822，95%CI 1.174-2.718，interval scale of QRSd was 40 ms）and left atrial diameter （P=0.045，HR 1.042，95%CI 1.001-1.086）were independent risk factors for AF occurrence. Receiver operating charac? teristic curve suggested that change value of QRSd in lead V6 could predict AF occurrence，especially for patients with long pre-implantation QRSd（≥ 120 ms，area under the curve was 0.826，95%CI 0.685-0.967）.【Conclusions】Change value of QRSd in lead V6 seems to be positive correlated with post-implantation AF occurrence.