Abstract: A theoretical study is made of the response of the vertical circulations in the atmosphere to the sea surface temperature in tropical oceans,with a linear steady two-dimensional model. In this model the boundary layer over the well-miring layer of the tropical ocean and the equatorial lateral boundary layer are considered. The results show that when the anomaly of SST in the eastern part of the ocean is warmer than that of in the western, the meridional circulation in the atmosphere (Hadley cell) would be strengthened and zonal circulation (Walker cell, in Pacific) would be weakened; when the anomaly of SST in the western is warmer than that in the eastern, the zonal circulation would be strengthened and the meridional circulation would be weakened. These agree with the observational data.