Twenty patients with congenital aortic stenosis excluding valvular stenosis were studied beween April 1980 and April 1984 at Seoul National University Hospital. The clinical and radiologic findings with the emphasis on thecineangiographies were analyzed separately according to the type of aortic stenosis as subaortic and supravalvularaortic stenosis. The summaries of the analysis are as follows: 1. Among the 20 cases, 12 cases were subaorticstenosis and 8 cases were supravalvular stenosis. 2. The anatomic types of subaoritc stenosis were the discretemembranous type (8 cases), the fibromuscular type (2 cases) and the tunnel type (2 cases). 3. The obstruction ofsubaoritic 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 greater than that reported in mostother large series. 4. The anatomic types of 8 cases of supravalvular aortic stenosis were mainly focal type (7cases ) and 1 case of diffuse hypoplastic type. 5. The median left ventricular to aortic systolic pressuregradient of supravalvular stenosis was 75mmHg, and associated anomalies were seen in 6 cases(75%) with 3 cases ofsuspected mental retardation and facial abnormalities without definite hypercalcemia. 6. For accurate diagnosis ofcongenital aortic stenosis, retrograde left ventricular angiograms obtainend in axial pojections are of crucialimportance in demonstration of anatomic types of stenosis and associated anomalies. And supravalvular aorticinjection is sometimes helpful to outline the anatomy of the valve and to evaluate the degree of aorticregurgitation.