The highly-productive western North Pacific has experienced dramatic changes in oceanographic conditions and ecosystem structure, driven by climatic changes and anthropogenic interventions. We conducted comparative studies across NOWPAP countries (China, Japan, Korea and Russia) to evaluate regional differences in the responses of marine ecosystems to the changes in the NOWPAP sea area (33-52oN; 121-143oE) by a working group composed of natural and socioeconomic scientists. In 2011-2013, we analyzed spatial and temporal variability in oceanographic conditions and recruitments of major fish species in the NOWPAP sea area for the last 40 years. In 2013-2014, we tried to forecast changes in potential production of fisheries resources and evaluate risks and vulnerabilities, induced by climate change, in fisheries-dependent sectors across NOWPAP countries (China, Japan, Korea and Russia). We held 3 workshops. We hope this report provides scientific basis to decision makers in developing policy strategies that incorporate regional differences in 1) marine ecosystems supporting fish stocks, 2) vulnerability and adaptation of fisheries industries to climate change. This report is expected to contribute to comprehending the status and outlook of marine ecosystems supporting fisheries in the Northwest Pacific, and to extending regional policy makers’ knowledge and understanding for adapting fisheries sectors to climate change.