In order to clarify the developmental course of the maxillary sinus of children by tomography, I wished to obtain the average size of the head of male and female primary school pupils in each school year as the experimental data and measured the face and skull of 1742 pupils at 10 places. (1) The zygomatic arch width, external eye-orbit diameter, mandibular angle width and nasal height of male and female 3rd year pupils were found to be remarkably developed. The minimum frontal width of 5th year boys and 3rd year girls was also markedly developed. (2) The maximum head length, maximum head width, morphological upper face height and morphological face height of boys and girls in each school year were increasingly well developed. (3) The inter inner canthus width of all pupils in each school year was not increased.