Abstract: The relationship between the quasi-stationary planetary waves forced by topography and heat source during the Northern Hemisphere is investigated by means of a quasi-geostrophic,34-level spherical model with Rayleigh frictipn,Newlonian cooling and the horizontal eddy thermal diffusivity.The computed results show that when the basic flow in the tropical stratosphere is the westerly,the amplitude of quasi-stationary,planetary wave for zonal wave number 2 at middle and high latitudes during the Northern Hemispheric winter is larger;while when the basic flow in the tropical stratosphere is the easterly,It is smaller.This is in agreements with the actual observed results.The compted results also show that influence of the basic flow in the tropical troposphere on the quasi-stationary planetary waves,is larger than that of the basic flow in the tropical stratosphere on the quasi-stationary planetary waves