The features of rates of development of physical qualities are considered for youths of different somatotape in 15-17 years. Rotined change in the structure of increase of physical qualities of representatives of different types of somatic constitution. The calculations of sizes of changes of every separate component are resulted with subsequent factorization of the got values. Basic data for calculations were sizes of year-on-year increase of physical qualities. The structure of year-on-year increase of physical qualities substantially differs between itself.