Abstract: A time-dependent linear model on the equatorial beta plane is developed in this papar. Its vertical structure consists of two active layers above the thereto-cline with equal density and temperature and a quasi-quiescent with constant density layer below the thermocline. The results of numerical experiment show that the direLt influence of heat on the equatorial ocean is much smaller than that of wind stress. Nevertheless, through the tropical ocean-atmosphere interaction, the thermal forcing can result in the change of wind stress so that it is of determinant effect on the epuilibrium and anomalous development of the ocean-atmosphere circulateon.