Abstract: The paper takes the Wu-hua County, Guang-dong Province as an example to discuss the relationship between the development of rural energy and the improvement of ecological environment. The Wu-hua County is located in sub-tropic region of Suothern China. It is a mountainous district and soil and water were seriously eroded. People were quite impoverished. All these were happened before the development of rural energy. After 5 years work on the development of rural energy all the situations of the County have been greatly changed especially a new point of view to be discovered.From the Wu-hua County, authors of the paper found that the synthetic development of rural energy is close related to make the tural economy more prosperously, heighten the living standard of rural people and improve the rural ecological environment. The relationship between the development of rural energy and the rural ecological environment is to help each other forward and also condition each other. Hence, when the agricultural engineers plan the development of rural energy with systems engineering who must put the whole county as a large system and the development of rural energy is only a sub-system under this large system. In this Way it will be possible to develop the rural energy and protect the rural environment from pollution simultaneously. The result is to make the agricultural industry more sustainable, stable and coordinate.