The association between secular trends in height and changes in bone maturation was investigated. The first group of subjects consisted of a total of 1,057 girls and 1,055 boys who participated in a health research project conducted in Japan and China in 1986. The second group of subjects consisted of a total of 382 girls and 629 boys who participated in a research project examining bone mineral density in 1996. The skeletal maturity score was assessed using the Tanner-Whitehouse 2 RUS method. The Wilcoxon rank sum test was then applied to examine the significance of the differences between the 1986 and the 1996 groups. The 1996 children had not matured more quickly than the 1986 children, and the children in both groups reached the given scores at almost the same ages. In girls, there was a small difference between the groups at 7 years of age, but this difference decreased from the age of 8 years onwards. Some apparent differences arose at ages 14 and 15 years, but these differences ceased by the age of 16 years in girls. No differences were found for boys between the ages of 7 and 17 years, except for 12-year-olds. We did not detect a notable difference in bone maturation between the 1986 and 1996 groups of children, and no differences in height were observed during the same period. Our findings suggest that bone maturation reflects the secular trend in growth.