This article provides data on the inheritance of fiber yield and fiber length in first generation hybrid forms derived from genotypically different forms of G.hirsitum L species medium fiber cotton. The obtained results showed that in hybrids F1 dominance of one of the parent forms and intermediate inhe¬ritance by the characteristics of yield and length of fibre is manifested in hybrids of forms with different ge¬notype, with high and medium index, and inheritance by the type of positive superdomination, i.e. positive heterosis - in hybrids of forms with medium and high index.