The results of research on marine contamination in the regional areas (Kara Sea, Barents Sea) in the Arctic Ocean were reported at the 3rd and 4th Symposia on Global Environment. In the present research, the authors carried out flow analysis in the whole region of the Arctic Ocean and concentration analysis of radioactive materials based on the release scenario, made comparative studies of flow and concentration analyses in the regional areas, and examined the consistency of the results obtained by both models and the characteristics of diminution in material concentration in the Arctic Seas.