Abstract: The harmonic synthesis method was applied to generate fluctuating wind velocity for coarse grids. Turbulent inlet for large eddy simulation (LES) was calculated by bilinear interpolation and cross-correlation modification. The spectral element method (SEM) was introduced to simulate two kinds of three-dimensional hills by LES. The results were compared to the wind-tunnel tests and finite volume method (FVM) numerical simulation. It was found that LES can accurately predict the wind speed distribution and turbulence characteristics of hilly terrain. Compared to FVM, SEM is more efficient and its applications in the fields of wind fields prediction for complex terrain is promising.