VSD is the most common congenital cardiac malformation and the natural history depends not only on the age of patients and the size of defect but the subtype of VSD as well, important factor in clinical management of those patients. In 110 patients, with surgically repaired VSD in Yonsei Medical Center in 1984, the subtype of VSDs evaluated by surgical observation were correlated with LV angiogram findings to verify the incidence of subtype in Korean and the diagnostic accuracy to predict the subtype by angiogram. 1. 110 patients included 64 boys and 46 girls, the age ranged from 3 months to 14 years(average 4.6 years old) 2. Angiographic findings were interpreted as follows; a. Perimembranous defects were profiled in LAO 60。 LV angiogram and located below the aortic valve. In inlet excavation the shunted blood opacified the recess between septal leaflet of tricuspid valve and interventricular septum in early phase, in infundibular excavation opacified the recess between ante ior leaflet of TV and anterior free wall of RV and in trabecular excavation the shunted blood traversed anterior portion of TV ring, opacified trabecular portion of RV cavity. b. Subarterial types were profilled in RAO 30。 LV angiogram, just below aortic valve as well as pulmonic valve. Total infundibular defects were profilled in RAO 30。 and LAO 60。 LV angiogram subaortic in location in both views. c. In muscular VSD the profilled angle was varied according to the subtype but the defects were separated from the aortic valve as muscular septum interposed between the aortic valve and the defect. 3. The incidence of subtype of VSDs evaluated bgy surgical observation were as follows. Subarterial type 32 cases(29.1%) Total infundibular defect 5 cases(4.5%) Perimembranous type 73 cases(66.3%) Infundibular excavation 32cases(29.1%) Trabecular excavation 28 cases(25.5%) Inlet excavation 10cases(9.1%) Inlet excavation 3cases(2.7%) Mixed 1 cases(0.9%) Total 63.6% of VSD, were the varieties of the infundibular septum type. 4. The prediction of VSD subtype according to the angiographic findings described above, were compared to the surgical observation. Diagnostic rate was 100% in perimembranous type, 75% in subarterial type, 0% in total infundibular type, so 88% of cases were in accordance with the surgical findings.