Abstract: The global energy crisis and climate change promote the rapid development of wind power generation in the whole world. To know well the distribution of wind energy resource is the key step to expand wind power generation project. This paper firstly reviews the wind energy resource assessment technologies of the past 10 years and expatiates on the numerical simulation technology playing an important role in this field. The numerical simulation of wind energy resource is able to give the distribution of wind energy resource at any interested height and to reveal the wind resources undetected by the observational data. Moreover, it is also able to overcome the lack of observational data over the sea to assess the offshore wind resources. The distributions of wind resources in Qinghai and Jiangsu province in higher resolution were simulated by the CMA's numerical modeling system and the simulated results were checked by the observational data. It is shown that the CMA's numerical modeling system is able to accurately simulate the distributive trend of wind resource in the concerned region, but there are systemic errors in the size of wind resource between simulation and observation. The mask's observed data could be used to correct simulated results. It is also indicated that the numerical simulation method combined with wind resource measurement is the effective technology for wind resource assessment. In the end, this paper discusses the prospect of Chinese numerical simulation technology for wind resource assessment, and emphasizes that it is urgent to develop micro-scale numerical model independently.