This study was conducted to clarify the relationship of hyoid bone position to tongue position and mandible when malocclusion is categorized in the bilateral and in the vertical components. Five groups of samples (normal occlusion, unilateral and bilateral cross-bite, open bite, deep-bite) were selected for his investigation by utilizing the cephalograms. On the basis study, the following conclusions were obtained, 1. In the normal group the mean hyoid position (H-M) was 9.83±4.27mm. The mean distance of hyoid body to tongue dorsum (H-T) was 52.17±6.70mm. The ratio of H-M/H-T was 18.59%. 2. In all malocclusion groups, the hyoid position (H-M) was found to be larger than that of the norm except the deep overbite group. 3. The tongue dorsum position (H-T) was increased, compared to that of norm, in all malocclusion groups. 4. Hyoid positron (H-M) was found to show high correlation to the ratio of H-M/H-T, H-T, PI-T (0.890, 0.699, 0.455) 5. The hyoid position (H-M) was found to show low correlation to the measurements of mandible, but among them the ODI was found to show conversely a little higher correlation against hyoid positron (H-M).