The cerebral angiography was performed in a series of 101 normal Korean, children under twenty years of agefrom 1958 to 1966 inclusive in order to determine the roentgenologic aspects of normal arterial variations anddistributions. Practically all cases were done by the percutaneous method, and the roentgenographic technique inchildren is essentially the same as that used in adults. In our study, the configuration of arteries, the behaviorof intracranial vessels, the size of arteries and the position of major arterial trunks have been observed inconnection with the pathological conditions. The results were summarized as follows: 1) The calibers of internalcarotid arteries in the region of the intracavernous portion and/or intrapetrosal portion were: maximum diameter4.8+0.11mm, minimum diameter 3.5+0.2mm and average normal diameter ranged from 4.1mm to 4.3mm. 2) The calibers ofinternal carotid arteries in the region of the carotid siphon were: maximum diameter 3.1+0.21mm, minimum diameter2.7+0.43mm, and average normal diameter ranged from 2.8mm to 3.0mm. 3) The calibers of anterior cerebral arterieswere: maximum diameter 1.7+0.17mm, minimum diameter 1.3+0.09mm, and average normal diameter ranged from 1.4mm to1.6mm. 4) The calibers of middle cerebral arteries were: maximum diameter 1.7+0.11mm, minimum diameter 1.2+0.11mm,and average normal diameter ranged from 1.4mm to 1.6mm. 5) The calibers of posterior cerebral arteries were:maximu diameter 1.5+0.24mm, minimum diameter 0.8mm, and average normal diameter ranged from 1.1mm to 1.3mm 6) Thedistance between ascending vertical portion of the anterior cerebral arteries and inner table of the frontal bonein the lateral projection of the carotid angiograms were: maximu distance 48.9+1.11mm, minimum distance37.3+1.36mm, and average normal distance ies in between 39mm and 41mm. 7) The distance between the upper portionof teh pericallosal arteries and inner table of the parietal bone in the lateral projection of the carotidangiograms were: maximum distance 41.5+2.39mm, minimum distance 34.2+2.25mm, and average normal distance lies inbetween 37mm and 39mm. 8) The distance between the lower portion of the pericallosal arteries and inner table ofthe parietal bone in the lateral projection of the carotid angiograms were: maximum distance 48.0+2.97mm, minimumdistance 40.0mm, and average normal distance lies in between 44mm and 46mm. 9) Normal deviations of the anteriorcerebral arteries to the midline in the anteroposterior projection of the carotid angiogram were: 60% within 2mm,38% within 4mm, and 2% within 6mm. 10) The morphological variations of the internal carotid arteries in the regionof the carotid siphon and intracavernous portion were: simple S type 70%, double S type 8% and transitional type 22%. 11) The distances between angiographic sylvian points and inner table of the temporal bone in theanteroposterior projection of the carotid angiograms were: maximum distance 37.4+1.12mm, minimum distance27.0+3.38mm, and average normal distance lies in between 32mm and 34mm. 12) The distances between inner mostlimits of the middle cerebral arteries roughly outlining the island of Reil and inner table of the temporal bonein the anteroposterior projection of the carotid angiogram were: maximum distance 28.2+0.44mm, minimum distance21.8+1.25mm and average normal distance lies in between 23mm to 25mm. 13) The distance from the clinoparietal lineto the lowest major branch of the middle cerebral artery decreases with advancing age to approach the relationshipfound in the adult. The average normal distance lies in between 9mm and 10mm. 14) The distances between the mostlateral branch of lenticulostriate arteries and the midline in the anteroposterior projection of the carotidangiogram were: maximum distance 33.3+1.39mm, minimum distance 26.5+3.46mm, and average normal distance lies inbetween 29mm and 31mm. 15) The distance between the most medial branch of the lenticulostriate arteries and themidline in the anteroposterior projection of the carotid agiogram were: maximum distance 22.3+2.21mm, minimumdistance 18.5+2.01mm, and average normal distance lies in between 19mm and 21mm. 16) The filling of two anteriorcerebral arteries were not uncommon in children and encountered in 28%. 17) The filling of posterior cerebralartery was encountered in 31.4% of cases. 18) The visualization of the posterior communicating artery andophthalmic artery were encountered in 63.4% and 75%, respectively. 19) The visua lization of the anteriorchoroidal artery was encountered in 91%.