The structure of sedimentary basins of the Russian Arctic Seas is studied and illustrated by a number of maps, cross-sections and geophysical models. The calculated density models of the Earth crust illustrate the deep structure of the main blocks of the crust. Five major gas-condensate and gas fields are discovered here: three (Shtokman, Ludlov, Ledovoe) in the Barents and two (Leningrad and Rusanov) in the Kara Sea.Geological and geophysical characteristics...