This study was undertaken to investigate the exact values of the cephalometric standards of Hellman dental age III B groups of Korean in the reontgenocephalometry. The subjects consisted of 25 males and the same number of females with the normal occlusion and acceptable profile. Each lateral cephalometric head film was taken with the teeth in occlusion and the Focal-film distance was 300cm. Their linear and angular measurements were made directly. The following conclusions were obtained; 1) The author made the tables of standard deviation from the measured values. 2) The degree of the facial convexity of Korean children was larger than that of the white. 3) The labial inclination of the lower central incisor in male was a little greater than that in female.