The recognize the problems in malocclusion by roentgenocephalograms, the author designed a new pentagonal frame based on maxillary and mandibular bones. The subjects consisted of 44 normal occlusion (20 male and 24 female), 44 Class II division 1 malocclusions (15 male and 29 female) and 67 Class III malocclusions (31 male and 36 female). The results are as follows; 1. In normal group, the maxillary and mandibular skeletons of femal are placed more closely to FH plane so more anteriorly and upward that those male. 2. In normal group, the posterior vertical hcight is longer in male than in female and the upper anterior teeth of female are in more labioversion than those of male. 3. By the X, Y coordinate values in pentagonal frame, it is helpful to recognize certain problems in malocclusions. 4. The posterior vertical height is a good indicator in detecting Angle´s Class III malocclusion. 5. The maxillary and mandibular body length, the anterior point of maxillary and mandibular body length and the axial inclination of upper and lower anterior teeth can useful in discerning Angle´s Class II & Class III malocclusion.