Aim. To determine the stability and plasticity of the grain weight per spike, 1000-kernel weight and yield of mid-high and semi-dwarf winter bread wheat accessions. Results and Discussion. We determined the stability and plasticity of the grain weight per spike, 1000-kernel weight and yield of mid-high and semi-dwarf winter bread wheat accessions. The meteorological conditions during the vegetation periods in 2015-2018 made it possible to differentiate winter bread wheat accessions by stability and plasticity of the grain weight per spike, 1000-kernel weight and yield. The best winter bread wheat accessions of the NCPGRU’s collection, which were distinguished by grain weight per spike, 1000-kernel weight and yield, were evaluated for their stability degree (Sd) and plasticity level by regression coefficient. It was found that the proportion of accessions with high homeostaticity (bi <1) for the traits under investigation, which was most typical for mid-genotypes, was 70.6% for the yield, 64.7% for the 1000-kernel weight and 58.8% for the grain weight per spike, which is important for breeding for adaptability. Sources of high homeostaticity with a regression coefficient of <1 for the grain weight per spike (Zorepad Bilotserkovskyi, Anatoliia (UKR)); 1000-kernel weight (Krasa Laniv (UKR); Ilona (SVK)); yield (Pochaina, Krasa Laniv (UKR); Adel, Kazachka (RUS); OR2070011 (USA); Ilona (SVK), Darunok Podillia (UKR)) were singled out. In addition, we selected accessions with a wide environmental response (bi> 1), which can best fulfill their yield capacity under improved growing conditions or on an increased soil fertility, for the grain weight per spike (Zorepad Bilotserkovskiy, Anatoliia (UKR)); 1000-kernel weight (Harmonika, Prynada (UKR), Moskvich (RUS), Aran (AZE)); yield (Biloretskovskyi Zorepad, Prynada (UKR), Morozko, Vid (RUS)). Conclusions. The study of collection material of different eco- geographical origin enabled us to identify new sources of grain weight per spike, 1000-kernel weight and yield with increased environmental plasticity and stability, the use of which in breeding programs will contribute to the development of new highly productive and more valuable genotypes. Sources of high homeostaticity in winter bread wheat are valuable starting material to develop new highly adaptive varieties.