Abstract: By using IAP-GCM,it is proved that the anomaly in the Antarctic ice is one of the important mechanisms to cause intraseasonal oscillation in the global atmosphere.The time sequence of pentadly mean depature field is analized in this paper by using the band pass filtering scheme.With special attention to the characteristics of 30-60 day oscillation in the response field,it was found that the global atmosphere behaves long-time teleresponse to an anomalous external forcing from the Antarctic sea ice,whose period ranges from thirty to sixty days.30-60 day oscillation plays an important role in the forcing field,whose vertical structure,zonal propagation and distribution characteristics in the model atmosphere is similar to that in the real atmosphere.