Longitudinal and transversal arch of children's feet are change, in certain range, during their growth, but generally they show up affect of physical exercise and the body weight on feet construction. The studies have been performed on the group of 72 boys at the age of 13-14, who were training hand-ball game. They were pupils of primary schools in Szczecin and Świdwin. The purpose of this work was mainly to describe morphological construction of the boys feet and to qualify connection between children body building and longitudinal and transversal arch of their feet. Longitudinal arch of the feet was measured in accordance to Clarke's angle method, transversal-with heel's angle. The body building type was marked by Rohrer's index. The analysis showed up, that over half of the boys, who were training hand-ball game have feet correctly builded in their longitudinal and transversal arch. The boys' left feet have more often correct structure than the right ones. Almost all of the children have slim type of the body building. Connection between lower longitudinal arch of feet and large body weight have been observed. Correlation between type of the body building and transversal arch of the feet have been not noticed.