The effect of marine mesoscale processes on spatial variation of fisheries is an important part of fishery resources assessment.In order to clarify the response relationship between fishery resource abundance in the Kuroshio-Oyashio confluence region （145°E-165°E, 35°N-45°N） and mesoscale eddies, this study utilized data from mid-pelagic trawl catches and satellite altimetry collected during research cruises in the Northwest Pacific from June to August 2021-2023 by the "Songhang" of Shanghai Ocean University research vessel. The study investigated the relationship between catch density and environmental factors as well as eddies.The results indicate a significant spatial correlation between sea surface temperature, chlorophyll-a mass concentration, and the distribution of fishing density in the fishing grounds. These factors predominantly influence the resource abundance of middle and pelagic fishery. The average fish catch yield is higher in the sea area north of 40°N compared to those south of it. Within 1-2 times the radius of cyclonic eddies, there is a notably positive abnormality in chlorophyll-a mass concentration. Conversely, in anticyclonic eddies, there is a positive abnormality in chlorophyll-a mass concentration in the northeastern part and reduced mass concentrations elsewhere.Within a radius of two times the eddy, fish aggregation was favored to the south of the cyclonic eddy and to the north of the anticyclone. Although the cyclonic eddies are nutrient eddies, their accompanying upwelling leads to low water temperatures, which are not favorable for fish aggregation. Marine organisms in the Kuroshio-Oyashio confluence region tend to aggregate in the southern part of the cyclonic eddy and the northern part of the anticyclonic eddy.This study can provide a scientific basis for short-term fishery forecasting and prediction of the center of gravity of the fishery in the Northwest Pacific Ocean, while the fishery changes caused by the inter-annual dynamic difference of the Kuroshio Current axis still need to be further investigated.