This paper highlights the SST interdecadal variability over the Eastern North Pacific and its connection with East Asian winter monsoon (EAWM) on decadal timescales. Aside from PDO pattern, the SST interdecadal variation is the most significant over IP region, where there is the intense air-sea interaction involved with EAWM, including both wind stress and latent heat flux. A possible explanation for the phase change of PDO is related to the localized atmospheric forcing and the "upstream" winter monsoon. SSTA interdecadal variation over the IP regions is the 'bridge' linking the coupled ocean-atmosphere interaction between midlatitude Pacific and the tropical Pacific.