Seventy eight infants and children aged from 2 to 7 years and 5 adults included as a control group were investigated to clarify the characteristics of foot growth and to define the relationship between the shape of foot sole contact surface and the structure of foot skeleton. Photographs of foot sole contact surface and the structure of foot skeleton were taken for both feet, using a pedoscope and X-ray photographs respectively.
　1) The contact surface and the noncontact and relative noncontact area all increased with age, and for the relative noncontact area it nearly reached the adult's average at age 7. No significant correlation was found between age and inclination angle of Os metatarsal V, Calcaneus and Talus contact point.
　2) Pursuing the growth of the foot sole contact surface for one year the contact and noncontact area increased significantly, but the growth of the relative noncontact area was somewhat slight, though significant. From these results it may be suggested that the longitudinal arch of the fundamental structure of foot skeleton for these ages were nearly as large as that of the adult's.
　3) The relative noncontact area and the inclination angle decreased after working. Viewing the foot sole contact surface, two types were found, one with small contact surface and small inclination angle and the other with small contact surface and large inclination angle similar to the adult's.
　4) From these results it can be suggested that the development of the relative noncontact area should be differentiated from that of the longitudinal arch in considering growth of the foot, and it should be considered not only the shape of the foot sole contact surface, but also the structure of foot skeleton.

DESCENTE SPORTS SCIENCE Vol.28/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE