The purpose of this study was to investigate the normal range of condylar movement of normal adults. The author has observed roentgenographic images of four serial positions of condylar head taken by modified transcranail lateral oblique projection. The serial positions are centric occlusion, rest position, 1 inch open position and maximal open position. The results were obtained as follow; 1. Inter-incisal distance was 46.85㎜ in maximal open position. 2. The length between the deepest point of glenoid fossa and summit of condylar head in rest position was wider than that in centric occlusion by 0.8㎜. 3. In 1 inch open position, condylar head moved forward from the standard line in 12.64㎜ of horizontal direction and moved downwards from the standard line in 1.84㎜ of vertical direction. 4. In maximal open position, condylar head moved forward from the standard line in 19.06㎜ of horizontal direction and moved downwards from thestanard line in 0.4㎜ of vertical direction. 5. In centric occlusion, the width between glenoid fossa and margin of condylar head was greater in the posterior portion than in the anterior portion by 0.4㎜. 6. Except for the estimated figures of 1 inch open position, all of the estimated figures was greater in male than in female.