The basal vein of Rosenthal lies on the surface of the brain base, runs around the brain stem, drains posteriorly into the galenic system and usually outlines important anatomical structures including anterior perforating substance, uncus, cerebral peduncle and quadrigeminal cistern, even though it may show anatomic variations. The radiologic measurement of basal cerebral vein was performed in 48 normal adults. In lateral projection, the lowest point, roughly corresponding to the anterior border of cerebral peduncle, was related to the baselines which pass through the nasion and lambda, and tuberculum sellae and lambda respectively. In AP projection th eknee and the ankle were chosen for the measurement. 1. NR/NL is approximately located at the mid point of the line which pass through nasion and lambda in figure 1. 2. TR”/TL is nearly located at one-third of the line which pass through tuberculum sella and lambda in figure 2. 3. R2M/NM is usually located within the range of 3 % and R1 appears located at the medial aspect of R2 within the range of 5mm in figure 3.