Abstract: The solutions of the downslope motions over a slope terrain are solved analytically in terms of the atmospheric wave equations with a two-layer model. The physical meanings of the solutions are discussed. As the lower layer of the atmosphere is stable and deep with strong wind the solution represents strong downslope wind, while the lower part is strong stable with light wind the drainage flow is obtained. The dependence of the strength of downslope motion near the surface on the atmospheric stratification, wind field structure as well as Scorer parameter is also examined.