Desmids of the Khrebtovyi nature reserve (Polar Ural) were investigated in July 2008. 88 desmids species and varieties were identified in 14 thermokarst lakes and one mountain lake. 73 taxa were identified to species, 7 to variety. Eight taxes were identified to genus. Representatives of found desmids belong to the Zygnematales and Desmidiaceae orders and the Mesotaeniaceae, Closteriaceae, and Desmidiales families. The highest species diversity was found in Desmidiales with 88 species of 18 genera. Cosmarium had the maximal species richness. Rare species were found in one place and they represented 59% of total species number. 22 species being new to polar region and the Khrebtovyi reserve were collected.