We have experienced a case of aortic dissecting aneurysm in pregnant woman. She felt initially severe chest pain which was radiated to the neck on the 3days before delivery. Thereafter dyspnea and generalized edema were developed for 1 month after delivery. She was diagnosed as aortic dissection, Debakey typeII. During cardiopulmonary bypass, the selective cerebral perfusion was done through the right and left commom carotid arteries. Aortic replacement with Hemashield vascular graft and reimplantation of innominate artery, resuspension of aortic valve, repair of intimal tear were performed. The postoperative course was uneventful.