The state-of-art Computational Fluid Dynamics (CFD) codes FLUENT is applied in a fine-scale simulation of the wind field over a complex terrain.Several numerical tests are performed to validate the capability of FLUENT on describing the wind field details over a complex terrain.The results of the numerical tests show that FLUENT can simulate the wind field over extremely complex terrain,which cannot be simulated by mesoscale models.The reason why FLUENT can cope with extremely complex terrain,which can not be coped with by mesoscale models,relies on some particular techniques adopted by FLUENT,such as computer-aided design (CAD) technique,unstructured grid technique and finite volume method.Compared with mesoscale models,FLUENT can describe terrain in much more accurate details and can provide wind simulation results with higher resolution and more accuracy.