The pervalence od normal occlusion and malocclusion was assessed by Angle’s Classification method for 8989 school students at 7-22 years in Seoul. The occurrence of malocclusion and the need for orthodontic treatment was 61 per cent among them. Results indicated no significant differences between the sexes for the occlusal relationships of the mandible to the maxille. The prevalence of Class I, Class II, and Class III malocclusion in all malocclusion was shown to be Class I, 45.7 per cent ; Class II, 7.6 per cent ; and Class III, 7.9 per cent. Class II Division 1 was observed to occur four times frequently compared to Class II Division 2 in Class II malocclusions. Class III malocclusion was shown to occur more frequently compared that of Caucasians.