Objective: To observe the distribution characteristics of sex differences in physical growth among children and adolescents aged 6-15 years in Taiwan, China from 2007 to 2024, so as to provide clues for improving growth assessment standards and promoting the health of children and adolescents. Methods: Using publicly available height and weight data for children and adolescents aged 6-15 years in Taiwan, China from 2007 to 2024 released by the statistics agency of the Taiwan education authorities, sex difference indices were analyzed. Growth curve charts and Pearson correlation were used to analyze the correlation between height/weight and year, as well as trends of change with age and year. These were compared with data from the 8th National Survey on Students Constitution and Health in 2019, covering Han and ethnic minority groups aged 6-15 years in mainland China. Results: The sex difference index for height among children and adolescents in Taiwan, China ranged from -1.20% to 6.67%, showed a trend of decreasing first and then increasing with age. The sex difference index for weight ranged from 3.76% to 19.15%, exhibited an age related trend of a slight initial increase, followed by a decrease, and then an increase. The sex difference indices for height in the 12-15 age groups and for weight in the 15-year-old group were positively correlated with the year ( r =0.74, 0.66, 0.61, 0.92 ; 0.63), while the sex difference indices for weight in the 6-8 age groups were negatively correlated with the year ( r =-0.71, -0.77, -0.53) (all P <0.05). In 2024, the height of children and adolescents in Taiwan, China increased gradually with age, but the growth rate for girls slowed down after age 12. A "two crossover" was observed in height between boys and girls, with boys being taller than girls in the 6-9 age range and after age 12. Weight for both sexes gradually increases with age, but boys have greater weight than girls at all ages. In 2019, the sexual differences in body size among children and adolescents in the Taiwan region, China (the sex difference indices for height:-0.96% to 6.49%；the sex difference indices for weight:4.69%-17.89%) fell within the variation ranges of counterparts in mainland China (the sex difference indices for height:-5.43% to 7.69%；the sex difference indices for weight:-10.12% to 21.56%). Conclusion The sex differences in physical growth among children and adolescents in Taiwan, China are dynamically changing with age and over the long term.