Because a significant portion of the topography in Japan is characterized by steep, complex terrain, which results in a complex spatial distribution of wind speed, great care is necessary for selecting a site for the construction of Wind Turbine Generators (WTGs). We have developed a Computational Fluid Dynamics (CFD) model for unsteady flow called Research Institute for Applied Mechanics, Kyushu University, COMputational Prediction of Airflow over Complex Terrain (RIAM-COMPACTR). The RIAM-COMPACTR CFD model is based on Large-Eddy Simulation (LES) technique. In this paper, the numerical wind simulation over the Shiratakiyama wind farm was executed using the high resolution elevation data. In order to reproduce terrain-induced turbulence numerically, it is shown that both of the horizontal grid resolution and the time increment are extremely important. As a result, the numerical results also showed that it is possible to reproduce energy cascade of actual terrain-induced turbulence well in the frequency-wavenumber domain.