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 Taikoyama wind farm was executed using the high resolution elevation data. As a result, the numerical results obtained suggest that all the six WTGs in the Taikoyama wind farm are subject to significant influence from separated flow (terrain-induced turbulence) which is due to the topographical irregularity in front of WTGs. The new reproduction proposal was also done.