The comparison of the interdecadal and interannual characteristics of the atmosphere-ocean system between the tropical and extratropical Pacific is made in this paper.Results show that the interdecadal anomalies are more significant in the variance of the system anomaly in the North Pacific(NP),and the interannual and interdecadal anomalies are about equivaleut in the tropical Pacific(TP);the interdecadal change characters of the surface(shallow)layer of the ocean and the atmosphere aloft are unanimous in the same season and region,and their transition from a low mode to a high mode both occurred from the end of 1970s to the beginning of 1980s,with an exception for July in the NP,which is related to the stability of the stratification of sea temperature within the sub-surface layer;the interannual scale air-sea anomalies are associated with ENSO,which is most typical for January,then July in the TP,followed by January in the NP,and there is no visible relationship for July in the NP.