Authors analized 265 cases of cyanotic congenital heart disease in which cardiac catheterization and angiocardiography were done at the Department of Radiology, Seoul National University Hospital between April 1973 and August 1979. The resuls are as follows; 1. Among 265 cases, 178 patients were male and 87 patients were female. 240 patients were below the age of 20 and none was over 35 year. 2. The incidence of individual lesions are as follows; tetralogy of Fallot-176; double outlet right ventricle-20; pentalogy-12; trilogy-11; corrected transposition of great arteries-10; complete transposition of great arteries-8; pulmonary atresia-7; single ventricle-6; Ebstein's anomaly-5; total anomalous pulmonary venous return-4; tricuspid atresia-3; double outlet left ventricle-1; truncus arteriosus-1; hypoplastic left ventricle-1. 3. Fallot's tetralogy, pentalogy and trilogy were characteristic in their simple chest and angiocardiographic manifestations, but in a few cases of tetralogy and pentalogy it was difficult to differenciate them from double outlet right ventricle or pulmonary atresia. 4. In double outlet right ventricle and transposition of great arteries which are the pathologic spectrum resulting from abnormal contal growth, differential points were ventricular and great arterial loop patterns and their conections but it was very difficult to differentiate them from each other by single injection into one ventriclealong. 5. Ebstein's anomaly and total anomalous pulmonary venous return were so characteristic inangiocardiographic appearance that there was no problem in their differential diagnosis. 6. In 7 cases with double outlet right ventricle and transposition of great arteries, selective biventriculography was done and more accurate diagnosis could be made, which was quite difficult with one ventriculography alone. 7. In 31 cases, cineangiocardiography was done and it gave more accurate informations about the type and degree of pulmonarystenosis and over riding of aorta, the origin of great arteris from the ventricles and the location of the interventricular septum.