1. In the northwestern Pacific in winter, the Kuroshio Warm Current brings a huge amount of heat from lower latitude to mid-and high-latitude area (with the maximum in the 30 - 35° N latitude belt), the Oyashio cold current brings cold water from high latitude to middle latitude area (with the maximum in the 45 - 50° N latitude belt). They meet and mix and weaken near 40°N, then are transported eastward by the North Pacific Ocean Current.

2. The first three dominant patterns of the oceanic heat flux divergence anomaly in the upper ocean of the northwestern Pacific in winter are: The Kuroshio-Oyashio couple pattern (the lst component, 26% contribution) with 3.5 years period, the North Pacific Ocean Current pattern (the 2nd component, 16% contribution) with 3.5 years period too, the cold current dominant pattern (3rd component 11% contribution) with long terms period.

In the end of this paper, the close relationship between the time coefficients of the lst component in February and the index of the Western Pacific Subtropical High in May was shown, which suggest that the oceanic heat flux of the western boundary current of the North Pacific has some important effects on the climate.