The purpose of this study was to investigate growth change of the dental arch by examining the dentition (ie, 62 dental casts) of 6-11-year-old Japanese children, and comparing the findings with those obtained a half-century ago, in 1964. Arch length, dental arch width, and bucco-lingual inclination in first molar were measured and compured. The peak of growth change in the arch length was seen at an earlier stage as compared with previous findings, whereas at age 11 years the maxilla tended to be longer and the mandlbie shorter. The peak of growth change in the width of the molars was seen at an earlier stage as compared with before, but at age 11 years, the dental arch width tended to narrow. The peak in the growth of the maxillary bucco-lingual inclination in first molar was seen at age 7. The inclination changed in direction from a buccal inclination to the lingual side, the peak in the growth of the mandibular bucco-lingual inclination in first molar was also seen at age 7, and the inclination changed from a lingual inclination to a vertical direction. These findings suggest thet growth in the dentition of modern Japanese children shows earlier maturity and a narrowing of the dental arch width as compared with children in 1964. This suggests that although the peak of growth occurred at an early age, there was little subsequent growth. Furthermore, a growth peak was seen at the same period in the dental arch width and bucco-lingual inclination of the mandibular first molar, and the bucco-lingual inclination in first molar contributed to the narrowing of the dental arch width.