The species composition of diatoms in the Arctic ice, varies in different seas of Russian Arctic. In connection with this, there were distinguished two regions with high similarity in ice diatom complexes. The first region comprises the Chukchee Sea, the East Siberian Sea, and the Laptev Sea. The second one comprises the Kara Sea and the White Sea. The article underlines the further investigation necessity of the cryoflora of Arctic seas, which is conditioned by changes. Since the 1980’s, there has been being observed the global warming, which made the Arctic ecosystems particularly vulnerable. The winter warming in polar latitudes is expected to be 40 % more than the global warming. The next decrease in square of paleocrystic ice will lead to the transformation of Oceanic low, basic trophic structure, phytoplankton, that would inevitably be reflected in all chains of the trophic net.