Twenty patients with congenital aortic stenosis excluding valvular stenosis were studied between April 1980 and April 1984 at Seoul National University Hospital. The clinical and radiologic findings with the emphasis on the cinearngiographies were analyzed separately according to the type of aortic stenosis as subaortic and supravalvular aortic stenosis. The summaries of the analysis are as follows : 1. Among the 20 cases, 12 cases were subaortic stenosis and 8 cases were supravalvular stenosis. 2. The anatomic types of subaortic stenosis were the discrete membranous type (8 cases), the fibromuscular type (2 cases) and the tunnel type (2 cases). 3. The obstruction of subaortic types was usually severe, and the median left ventricular to aortic systolic pressure gradient was 60mmHg, and associated cardiac defects were found in 10 cases (84%), an incidence grater than that reported in most other large series. 4. The anatomic types of 8 cases of supravalvular aortic stenosis were mainly focal type (7 cases) and of diffuse hypoplastic type. 5. The mdian left ventricular to aortic systolic pressure gradient of supravalvular stenosis was 75 mmHg, and associated anomalies were seen in 6 cases (75%) with 3 cases of suspected mental retardation and facial abnormalities without definite hypercalcemia. 6. For accurate diagnosis of congenital aortic stenosis, retrograde left ventricular angiograms obtained in axial projections are of crucial importance in demonstration of anatomic types of stenosis and associated anomalies. And supravalvular aortic injection is sometimes helpful to outline the anatomy of the valve and to evaluate the degree of aortic regurgitation.