The development and wide distribution of new adaptive varieties in production is a promising and environmentally friendly way for the development of agriculture. A new, more modern, highly productive variety can ensure increased productivity, resistance of crops to stress factors, and promotes better use of natural and anthropogenic resources. The leading direction in breeding in the nearest future should be not the development of varieties in general, adapted to growing conditions, but the identification of varieties adapted to the stress-limiting environmental factors of a particular region, adaptive to the challenges of nature. In addition to the characteristics of the variety and environmental conditions, the forecrop also influences its productivity. Selection in some conditions may not reveal the potential of the genotype in others, which makes it important to obtain information on different growing environments of varieties at the early stages of breeding. The purpose of the current study was to determine the adaptive properties of promising winter barley varieties and lines according to various forecrops. The study was carried out from 2021 to 2023 to estimate the adaptability parameters of 20 winter barley varieties and lines developed by the FSBSI Agricultural Research Center “Donskoy” for various forecrops (weedfree fallow, peas, sunflower, winter wheat). To determine the indicators of homeostaticity (Hom) and selection value (Sc), stress resistance (Ymin–Ymax) and genetic flexibility ((Ymax+Ymin)/2), the coefficient of responsiveness to favorable growing conditions (Kr) and the indicator of the stability level of the variety (VSLI), there have been applied the methods of V.V. Khangildin and N.A. Litvinenko (1981), A.A. Rosielle and J. Hamblina as presented by A.A. Goncharenko (2005), V.A. Zykin (2005), E.D. Nettevich (2001). According to all forecrops, there have been identified the varieties distinguished by high parameters of environmental adaptability and stability. Stress-resistant genotypes included the lines ‘Parallelum 2016’ and ‘Parallelum 2017’ (Ymin–Ymax = 1.2, 1.1, respectively), which were distinguished by a set of stability indicators and have been recommended for use in the breeding process as sources of high stress resistance, low yield variability, capable of minimizing negative impact of growing conditions. The variety ‘Step’ proved to be adaptable (regression coefficient bi = 1.5), genetically flexible ((Ymin–Ymax)/2 = 7.7), and highly responsive to growing conditions (Kr = 1.53). The dynamics of productivity corresponded to changes in growing conditions, and to maximize a productivity level, there has been recommended to cultivate it on intensive forecrops.