Abstract:A linear, steady-state, baroclinic, primitive equation, threedimensional spectral model, in which Newtonian cooling, Rayleigh friction and biharmonic diffusion are included, is used to investigate the effects of idealized and actual topography on the planetary-scale forced stationary waves. Computational results confirm the qualitative analysis of β-plane barotropic theory. The orographically forced planetary waves have a equivalent barotropic vertical structure, and the rotational (nondivergent) component of perturbation flow field is dominant at middle and high latitudes, whereas the divergent(irrotational) component is mainly concentrated in the tropical region. The orographically forced stationary waves in the northern winter are dominated by zonal wave number two and the Tibetan Plateau plays a most important role in its maintenance, while the forcing by the orographic effect of either the Rocky mountaius or the Greenland Plateau seems to be of secondary importance.