Objective To introduce the application of coronary artery grafting in arterial switch operation using an “L” shaped incision in the wall of the pulmonary sinus. Methods Twenty-five children with abnormal ventricular aortic connections were treated by Arterial Switch Operation (ASO) using an “L” shaped incision in the wall of the pulmonary sinus, and four of them were treated by rapid two-stage ASO. Age ranged from 6 days to 66 months (6.8±14.8 months); weight ranged from 2.5 to 15 kg (4.7±2.9 kg). There were 19 cases of complete transposition of the great arteries (D-TGA), including 10 cases of intact ventricular septum (TGA-IVS) and 9 cases of combined ventricular septal defect (TGA-VSD); 6 cases of right ventricular double outlet with subpulmonary ventricular defect (Taussig-Bing, TBA). The coronary artery graft was performed by making an “L”-shaped incision in the corresponding adjacent pulmonary sinus wall to form a “portal” valve. In all cases, the heart resumed automatically after opening the ascending aorta during surgery, and no electrocardiographic or clinical manifestations of myocardial ischemia were found. All of them had stable circulation in the early stage. The cause of death was not clearly related to the coronary graft in any of the four early postoperative deaths. Conclusion Compared with the method of perforating the adjacent pulmonary sinus wall or “U” shaped vascular wall resection, the use of “L” shaped incision for coronary artery grafting can relatively increase the length of coronary artery, reduce the scope of freeing it, reduce the tension, and at the same time can reduce The “L” shaped incision for coronary grafting can increase the length of the coronary artery, reduce the extent of its freeing, reduce the tension, and reduce the torsion of the coronary artery after grafting.