Abstract: The exploitation and utilization of water resources is the mostimportant problem in developing arid areas of Northwest China.Water is not only a renewably natural resource but also a key factor in the environment. water conservation projects on large scale, must naturally lead to change of the water cycle and balance and a series of changes in the ecological environment, space-distingnished model in social-economic-ecological benefic is basic principle for its evaluation. Considering the relationship between water resource conditions and biological factor, it is important to study quantitative distinction by means of method of synthetical analysis. Establishmen of the system of environmentel managent, water resource control and nitorinq is necessary for incriesing capible of distinction in environment and ecological conditoins.