Abstract: Aiming at solving the problem of 3D scattering by an alluvial valley embedded in a layered half-space, the indirect boundary element method (IBEM) is established based on the free wave field calculated by using the direct stiffness method, and 3D scattering wave field simulated by using the Green’s functions of moving distributed loads in the layered half-space. The method is validated by comparison with known results, and numerical analyses are performed by examples of a valley embedded in a uniform half-space and in a single soil layer over elastic bedrock. The results show that the wave scattering around the valley embedded in a uniform half-pace are distinctively different from that in a layered half-space, the modals of the Rayleigh waves in a layered half-space have important effects on the displacement amplitudes around the valley, and also the stiffness and depth of the soil layer have important influence on the amplitudes and distribution of the displacement.