Objective：To investigate the effect of ventricular septal scars on the capture of left bundle branch during left bundle bracn pacing（LBBP）by cardiac magnetic resonance imaging（CMR）. Methods：A retrospective analysis was conducted on 52 patients intendea for LBBP，who were divided into a failure group and a success group based on whether the capture of left bundle branch was achieved. Segmental score of septal scarring was performed using CMR. Results：The score of the upper ventricular septal scar was an independent predictor of the success of LBBP capture. When the scar of the upper ventricular septum was less than 25%，the success rate of LBBP capture was 100%. Howerver，when the scar was equal to or more than，the failure rate of LBBP capture was 100%. Conclusion：Evaluating upper ventricular septal scars using CMR helps predict the success of LBBP capture，providing a reliable reference for the smooth execution of the surgery.