Based on the NCEP-reanalyzed atmospheric data and COADS SST data for the recent 50 years, interdecadal oscillation of the atmospheric circulation over the North Pacific Ocean in winter and its related temporal and spatial variations of SST were examined. The results indicate significant interdecadal variability of the atmospheric circulation over the North Pacific Ocean with principal periods of 16-22 years. Before 1977, PNA indices were basically negative but positive after 1977, a turning point year of interdecadal variability. The temporal change revealed by the first mode (EOF1 of the interdecadal component of the atmospheric height over the Pacific Ocean in winter, showed that 1977 was the only turning point in the recent 50 years, while the spatial distribution is of typical NPDO structure-before/after 1977 the atmospheric potential height over the North Pacific Ocean was higher/lower. SST changes associated with interdecadal oscillation of atmospheric circulation over the North Pacific Ocean in winter to large extent are the SST interdecadal components themselves, i.e. air-sea interaction possesses selectivity in time scale.