Discrete membranous subaortic stenosis[DMSS] is one of the subtype of congenital left ventricular outflow obstruction and can be associated with aortic regurgitation, infective endocarditis, ventricular obstruction. DMSS should be removed early, when diagnosed, and completely before secondary myocardial changes occur. Recently we experienced a case of DMSS with aortic regurgitation, and its left ventricular outflow tract obstruction[LVOTO] peak systolic gradient was 10lmmHg. Resection of membrane and aortic valve replacement is adequet for LVOTO and postoperative pressure gradient was 26mmHg. Postoperative echocardiogram shows no obstuctive membrane and well functioning aortic valve.