The purpose of this study was to obtain the lingual morphology(angulation, inclination, horizontal and vertical contour) and lingual arch form of Korean adult with normal occlusion in order to provide the basic datas for lingual brackets and ideal lingual archwire. Dental models of thirty person with normal occlusion(Male: 16, Female: 14) were selected for this study. Crown angulation, inclination, horizontal and vertical contour of lingual surfaces from Lt. 1st molar to Rt 1st molar of both upper and lower arch were measured. Lingual archform was studied from copied papers of dental models attached Fujita lingual bracket. The results of this study were summarized as follows : 1. The average angulation and inclination of lingual surfaces of all tooth types for Korean adults with normal occlusion were obtained. 2. The average horizontal and vertical contour of lingual surfaces of all tooth types were obtained. 3. There were similar figures in horizontal and vertical contour of lingual surfaces between upper and lower molars, upper and lower premolars, upper and lower canines, upper central and lateral incisors and lower central and lateral incisors respectively. It was possible that the use of those contour of bracket bases in common. 4. The average of lingual archform was provided, which was arch-shaped from canine to canine, linear along the premolars and molars with small offset bend between them, and where canines and premolars met, it was bent in a crank-shape. 5. There was no difference between lingual archform of male and that of female, although lingual archform of female was smaller than that of male in lower arch.