The impacts of variations in wind-forcing and the 18.6-year period tidal cycle on the concentration of dissolved oxygen (DO) in the intermediate waters of the subarctic North Pacific were analyzed. Our results demonstrate that the interannual changes of DO on isopycnal surfaces in the intermediate waters of the western subarctic Pacific can be described very accurately by a linear combination of the intensity of the Aleutian Low pressure system (North Pacific Index), the zonal wind stress (45¿N--52¿N, 165¿E--170¿W) in winter, and an annually averaged cubic of tidal amplitude for the central Aleutian and northern Kuril regions. The residual signal shows a good correlation with the temporal variations of DO in the Alaska Gyre.