Increasing the productivity and effi ciency of lamb production is a key factor in the competitiveness of the meat sheep industry. Therefore, in order to conduct sheep breeding more effectively it is necessary to apply new approaches to increase and improve the quality of products.Considerable interest are modern technologies involving the use of DNA markers, which are widely used in national breeding programs of a number of countries with developed animal husbandry and have a signifi cant impact on improving productivity indicators. A significant number of genes associated with meat productivity and meat quality have been identifi ed. However, in sheep breeding, information about the main genes or loci that affect the growth characteristics and productive traits of sheep is relatively limited. Due to the growing interest in the production of young mutton and lamb, priority is given to the study of genes that control meat productivity. The greatest interests are studies on the evaluation of the polymorphism of the growth hormone (GH) gene, which controls growth and development, as well as infl uencing the meat productivity of sheep. In this regard, the purpose of this work was research aimed at fi nding associations between polymorphic variants of the growth hormone gene and the qualitative characteristics of meat in meat and wool sheep of the genotype ½ Poll Dorset × ½ North Caucasian Meat and Wool breed bred in the Stavropol Territory. The data obtained when studying the histostructure of the m. Longissimus dorsi, depending on the genotypes of GH gene, indicate that the muscle tissue in individuals with AB and BB genotypes was characterized by a large number of muscle fi bers by 5,7 and 6,4 %, their smaller diameter by 7,6 and 9,2 %, and a lower content of connective tissue compared to animals with the genotype AA of GH gene.