Abstract: Based on the ERA-40 of the ECMWF daily data from 1957 to 2002，the band-pass filter and empirical orthogonal function (EOF) are implemented to investigate the 315K geopotential height in isentropic surface under the climatological mean.The first EOF model shows that the Arctic Oscillation (AO),the Antarctic Oscillation (AAO),and Pacific-North American (PNA) Teleconnection Pattern are the most distinct characters of the global low frequency oscillation.In this model,the interaction between AAO and AO is realized by meridional propagation of the intraseasonal oscillation (ISO) in the pacific.The second model shows that the characteristic of meridional and zonal propagation of ISO in the earth. In this model,the interaction between northern and southern hemispheric atmosphere is happened in Atlantic.When projected the EOF models on the time serials from 1957 to 2002 years,the result shows that the interdecadal variability of ISO is happened between the late 1970s and early 1980s,and gradually enhanced since the late 1980s.