The positional changes of the hyoid bone over entire growth period were studied by cephalometric method in order to determine the average position and average growth changes of the hyoid bone in koreans with normal occlusion. The materials included cephalometric radiographs obtained on twenty six males and twenty two females over the period from 8.7 years to 16.7 years of age in average. The results of this study might be summarized as follows: • The mean value and standard deviation of each measurement were obtained in each age and gender. • The hyoid bone tended to positioned forwardly in female at the age of 12.7, 14.7, and 16.7 years of age as compared with male. • The hyoid bone positioned more downwardly in male than in female.