Multistage unifocalization and complete repair have been performed for pulmonary atresia ventricular septal defect and major aortopulmonary collateral arteries. We reported a case that divided major aortopulmonary collateral artery was changed into an aneurysm that compressed the left main bronchus. A 1-year-8-month old boy was operated. The Rastelli operation with left pulmonary artery reconstructuion ligation of patent ductus arteriosus and take-down of right Blalock-Taussing shunt was performed on the patient who had pulmonary atreisia ventricular septal defect patent ductus arteriosus and MAPCA at 1 year and 8 months of his age. He previously underwent the unifocalization and right B-T shunt at 9 months of age,. He repeatedly had difficulty in weaning from the mechanical ventilator, After removing the aneurysm from the divided MAPCA that compressed the left main bronchus externally it was possible to wean him from the mechanical ventilator.