The dominant spatial patterns of the seasonal 500 hPa GPH field is induced by the EOF analysis. In winter, the first and fourth eigenvector show that the PEA and PNA-like anomalous flow pattern will prevail when the temporal coefficient is negative. Through the variation of the temporal coefficient of the eigenvector, prevailing of these flow patterns is significantly related to the variation of SST in equatorial Pacific. These relationships are insignificant in other three seasons. The dominant spatial patterns of the seasonal 500 hPa GPH field is induced by the EOF analysis. In winter, the first and fourth eigenvector show that the PEA and PNA-like anomalous flow pattern will prevail when the temporal coefficient is negative. the temporal coefficient of the eigenvector, prevailing of these flow patterns is significantly related to the variation of SST in equatorial Pacific. These relationships are insignificant in other three seasons.