The solutions of 3D scattering of oblique incident plane SV waves by a depositional valley in layered half-space are given in this paper on the basis of the solutions of a canyon.The accuracy of the method is verified by comparing with related results.It is found there is essential difference between the case of 3D wave scattering and that of 2D.So we can′t simply make the oblique incident plane SV wave decompose into inplane and antiplane directions in the cross-section of the valley

then calculate and superpose respectively.At the same time

many numerical calculations have been done for the researches of the scattering effect of the incidence angles.Taking an alluvial valley to be a one layer over half-space as an example

the effects of the stiffness and the thickness of the layer on the displacement are discussed.