The improvement of lodging resistance is one of the main tasks in winter barley breeding. It has been established that lodging resistance is associated with plant height. At present, the use of the semidwarf gene sdw1/denso in the breeding process is of great importance in the development of modern varieties. The semidwarf varieties with the gene sdw1/denso mutations are widely spread among the sowings of short-stem barley fodder varieties in the western states of US, in Canada, Australia and among spring brewery varieties in Europe. The varieties with the sdw1/denso gene are included in the genealogy of most modern barley varieties. The sdw1/denso gene has a pleiotropic effect, that is, it affects many traits, including the general adaptability and seed productivity of plants. In this regard, the purpose of the work was to compare the allelic polymorphism of the sdw1/denso gene with the results of the phenotypic assessment of economically valuable traits of winter barley. It was established that the sdw1/denso gene alleles are reliably associated with ‘grain size (coarseness)’ as one of the main parameters of yield. Thus, the dominant (mutant) allele of the sdw1/denso gene identified with the used CAPS-marker, can be recommended for selection of more productive genotypes.