A case of Annuloaortic Ectasia associated with Marfan syndrome and mitral regurgitation is treated surgically by Bentall`s method and mitral annuloplasty. The Annuloaortic Ectasia is frequently accompanied with Marfan syndrome, its definition is simply explained as the following; the marked dilatation of the sinuses of Valsalva and the aortic annulus as well as the huge aneurysm of the ascending aorta. As the operative finding, the intimal tearing was shown as circular and the both coronary ostia were changed the position into high up. The patient was taken a corrective operation replacing the ascending aorta and aortic valve with a composite graft[St. Jude medical valve 29mm, woven Dacron tubular graft 31mm]. The both coronary ostia were reimplanted on the graft with 4-0 prolene by continuous suture. Mitral annuloplasty was performed. After the operation, the patient developed both spontaneous pneumothorax, he improved state by the closed thoracostomy. He has been doing well, postoperatively.