By observing the correlationships between the characteristics of the facial pattern and the methods of establishing the position of the lower central incisor to the five reference lines on the lateral roentacenocephalograms, the author tried to fine the most useful method of them, the criteris of which were the independence of a vatiation according to facial patterns, the close rslationships with soft tissue and lip balance, and the simple and consistent usefulness in clinical practice. The subject consisted of forty normal occlusions, forty class II div 1 malocclusion, forty class III malocclusions, ten treated class II div 1 cases and ten treated class III cases, all were in 14-17 yrs of age. The findings of this study are as follows: 1. The position of the lower central incisor to FP, OP, MP and NB showed variations according to ANB, FMA, Facial convesity and holdaway angle, so it can be used consistently, regardlesss of the facial pattern. 3. The linear position of the incisal edge of the lower central incisor to AP line has a profound influence on harmonious soft tissue and lip balance.