The purpose of this study was to obtain the lingual morphology (size, angulation, contour, eminence) of adults with normal occlusion in order to provide the basic data for lingual bracket and lingual arch form in Korean. The subjects (Male: 50, Female: 50) were selected who have normal occlusion and dental casts were prepared. Tooth size, angulation, arch width, horizontal contour, lingual eminence were measured for all 28 teeth both upper and lower arch. The results were as follows: 1. Measuring items of all individual teeth for adults with normal occlusion were obtained. 2. In comparison tests, there was a statistically difference between intermolar widths (6 to 6) before occlusal reduction and intermolar width (6 to 6, 7 to 7) after occlusal reduction only, all the other measuring items showed no statistically differences. 3. There was small variation in horizontal contour of lingual surface on lower incisors and upper and lower bicuspids. The other teeth showed somewhat greater variations. 4. There was offset between canine and bicuspid in upper arch while there was no prominent offset in lower arch.