In-order to define what the average Class I malocclusion looks like, 72 Class I malocclusions were compared with corresponding measurements from 90 cases of normal occlusion sample. This sample was pbtained from the Deprtment of Orthodontics, Infirmary of Seoul National Universuty. 1. SNA, Fac(NP) to SN measurements were fignificantly different from the normal occlusions and smaller than the normal occlusion means. 2. Y axis to SN, Mandibular plane to SN, 1 to Occlusal plane, 1 to NB(linear) measurements were sigmificantly different from the normal occlusions and larger than the normal occlusions. 3. ANB, Occlusal plane to SN, AB to Occlusal plane, 1 to SN, 1 to SN, 1 to Occlusal plane measurements showed no significant difference between the means.