The research was carried out in 1998, with 3023 pupils (1504 males and 1519 females) in Đích Vong A primary school, Nguyen Tat Thanh secondary school and Nguyen Binh Khiêm secondary school, in Càu Giày District, Hanoi City. The result showed that physical strength of school pupils has developed without stopping and increased by age. They has grown both in height and weigh. There is difference indevelopment physical strength beetween two sexes. Speed of increasing height and weight was hight in age 10-15.
