The northwestern North Pacific is considered to be one of the most productive areas in the global ocean. Although the marginal zones along the Japanese and Kuril islands, Kamchatka Peninsula, and Aleutian Islands are certainly productive, recent studies do not always show high primary production values in the western subarctic gyre (WSG). In addition, a recent analysis of the biological pump in the WSG showed that, in contrast to what was previously reported, the vertical change of the particulate organic carbon flux with depth is large. Nevertheless, the biological pump in the northwestern North Pacific may function to draw down the partial pressure of CO2 in the surface water because the ratio of the organic carbon flux to inorganic carbon flux (Corg/Cinorg), the export flux, and the export ratio from the surface water are higher than those in other oceans. This article also introduces recent research on changes to the biological pump that might have been caused by global warming.