The trait ‘1000-grain weight’ is an important criterion of the adaptability of varieties, since this trait demonstrates the final correlation result between the variety and the environment during productivity formation. The purpose of the current study was to estimate the variability of such values as adaptability, stability, stress resistance and homeostasis according to the trait ‘1000-grain weight’ in 20 winter barley varieties and lines developed by the FSBSI “ARC “Donskoy”. The study on the estimation of adaptability parameters was carried out in the department of barley breeding and seed production on the experimental plots of the FSBSI “ARC “Donskoy” (Zernograd, Rostov Region) from 2021 to 2023. In order to calculate the adaptability parameters, there have been used such coefficients and indicators as an indicator of homeostasis (Hom), breeding value (Sc), stress resistance (Ymin–Ymax) and genetic flexibility ((Ymax +Ymin)/2), the coefficient of response to favorable growing conditions and an indicator of the variety stability level according to the relevant methods. There have been identified the varieties with high adaptability and stability parameters. The varieties ‘Marusya’ and ‘Step’ were identified as those adapted to the conditions of the region, capable to have large productivity and adapt to changing environmental conditions and reduce the value of ‘1000-grain weight’ to a lesser extent. The samples ‘Parallelum 2086’, ‘Pallidum 2100’ and ‘Parallelum 2136’ proved to be stable, capable to minimize unfavorable environmental conditions, show a weak response of a variety to changing cultivation conditions, capable to change dynamically the indicator of ‘1000-grain weight’ under the effect of a changing environment. The line ‘Pallidum 2100’ has proven to be stress-resistant ((Ymin – Ymax) = - 4.1, (Ymin +Ymax)/2=44.5). The above-mentioned varieties and lines possessed a complex of studied traits and were the most adapted to the formation of large, heavy grain.