The results of the assessment of winter rye according to the most important economically valuable characteristics in the nursery of competitive variety testing in the conditions of Central Yakutia are presented. Breeding of winter rye in Yakutia was started in 2002. Studies show that rare varieties can withstand the harsh Yakut winter. Extreme wintering conditions for winter rye plants are characterized by low-snow winters, when the snow cover, according to long-term average data, does not exceed 30 cm at minimum air temperatures up to -550 C. Varieties bred in the central and southern regions of Russia, as well as foreign varieties, freeze completely, except in cases of favorable winters. In this regard, the choice of starting material for hybridization is limited. The initial source material was obtained from SibNIIRS and consisted of samples from the collection of the N.I. Vavilov VIR, which successfully hibernate in the Novosibirsk region, as well as hybrid lines from the gray bread department of this institute for environmental testing in extreme winter conditions. The research was conducted at pilot site No. 5 of the grain breeding and seed production group of the M. G. Safronov Yakut Scientific Research Institute of Agriculture in 2022-2023.. 4 samples of winter rye were used as the material in the competitive variety testing. The local, zoned variety of winter rye «Cholbon» was chosen as the standard variety. In the conditions of Central Yakutia, the B-7 winter rye line demonstrated a high level of winter hardiness – 99.0%, the yield was 3.3 t/ha, and the weight of 1000 grains was 32.8 g. The standard Cholbon variety significantly exceeded the B-7, G-17, and G-12 lines in terms of yield, with increases from 0.4 to 0.9 t/ha at HCP0.5 = 0.4 t/ha. All the studied varieties were characterized by a high level of winter hardiness – 97.0% - 99.9%.