The research objective was to estimate current state of winter pastures in the conditions of the Re-public of Buryatia. The research problems were the definition of specific structure, productivity, chemi-cal and mineral composition of winter pastures grass. The research was conducted in the Tunkinsky area of the Republic of Buryatia where there were 5 experimental sites, on constant winter pastures with perennial grasses according to standard geobotanical methods. Botanical analysis of hay crops was carried out in 4 farm groups: ce-real, bean, sedge and motley grass. After division according to botanical groups all test samples were dried up and weighed. The analysis of vital forms was carried out according to I.G. Serebryakov’s method. The names of plants were given according to S.K. Cherepanov’s method. The productivity of surveyed pastures made 3-3.5 c/hectare of dry weight. Specific structure of surveyed winter pas-tures was diverse that was connected with soil and climatic, physiographic, orographical and other fac-tors. In the territory of surveyed pastures the plants relating to the following families were registered: Poaceae, Fabaceae, Cyperaceae, Amaranthaceae, Urticaceae, Polygonaceae, Rosaceae, Plantagina-ceae, Lamiaceae, Asteraceae and Rubiaceae. The grasses of winter pastures were 70-75 % plants of Poaceae family. The change of the content and ratio of nutrients in plants during winter period when the content of cellulose increased was observed and the amount of fat decreased. In studied sam-ples low maintenance of protein from 5.1 to 5.8 % for absolutely solid on sites 1, 3 and 5 was ob-served. As a part of grass of winter pastures the content of silicon dioxide was enough, but at the same time soluble ashes were not sufficient. On sites 4 and 5 sufficient content of calcium was ob-served. The studied winter pastures were in satis-factory condition, had sufficient area, productivity, the range and nutritiousness of grasses. First of all it is recommended to use pastures with low herb-age. For the improvement of specific structure, structure and increase the efficiency of winter pas-tures it is necessary to observe the correct number of cattle on pastures strictly.