The vitreousness of grain is an important trait taken into account by the state standards of many countries when determining its quality class. When creating new cultivars, this trait is controlled at all stages of breeding. The article presents the results of studying the vitreousness of grain cultivars of Samara Research Institute of Agriculture, related to the 4 stages of breeding covering the periods - 1957-1990 (stage I), 2003-2004 (stage II), 2007-2008 (stage III), 2012-2018 (stage IV). The study was carried out on the experimental field of Samara Research Institute of Agriculture during 2012-2020. Experimental plots with an accounting area of 20.0 m2 were placed in randomized blocks. Vitreousness was determined by the percentage of vitreous grains on the endosperm section in refined grain samples taken in 3 field replicates. The evaluation of the data obtained was carried out on the basis of 2-factor, one-way dispersion and correlation analyzes, parameters of stability and responsiveness according to the methods of Kilchevsky, Khotyleva, Eberhart-Russell, Khangildin, Nettevich. The dispersion of grain vitreousness was determined by environmental conditions – 61.2%, genotype factors and genotype/environmental interactions – 9.3% and 19.0%, respectively. Progress in breeding relative to the first stage was observed at the 2nd and 4th stages and was absent at the 3rd stage. According to the absolute values of vitreousness (91.8-94.3%), 4 cultivars were distinguished - Bezenchukskaya zolotistaya, Bezenchukskaya krepost, Bezenchukskaya nivaand Bezenchukskaya 210, belonging to the 4th stage. Values close to these (89.2-89.6%) were noted in the varieties of the 2nd stage - Bezenchukskaya stepnaya and Pamyaty Chekhovicha. Successful breeding for the vitreousness of durum wheat grain is associated with an improvement in the parameters of the stability of the formation of a trait in a variety of environmental conditions. Reliable genotypic correlations of glassiness, grain yield and macaroni color show the effectiveness of simultaneous selection for these traits. The absence of significant correlations of grain vitreousness with vegetation parameters, and quality, suggests the possibility of obtaining the necessary recombinations in the selection process. Genotypic correlation coefficients show the possibility of breeding productive cultivars with a high vitreousness of grain and a varied combination of parameters of the growing season and grain quality. Cultivars of the 4th stage, Bezenchukskaya zolotistaya and Bezenchukskaya krepost, were proposed as a initial material in breeding for grain vitreousness