In the context of the 2-L AGCM of Institute of Atmospheric Physics,Academia Sinica,numerical study is performed on the influence of the western Pacific warming pool(WPWP) upon summer general circulation and monsoon LFO.Evidence suggests that the WPWP SSTA gives rise to great change in the atmospheric circulation LFO,resulting in enhancement of lowfrequency variance of sea level pressure in the monsoon region,intensification of low-frequency signal of temperature variation in the mid-upper troposphere,modification in the space pattern of low-frequency disturbance,displaying more clearly a wavetrain ranging north out of the WPWP, change in LFO phase(time domain)and revealing even more evidently the cross-equatorial propagation of low-frequency variation from the Southern Hemisphere.