Abstract: Northwest arid area is one of areas that will be exploited in the great development of West China. Making good use of water resources is basic assurance of the sustainable development of the area economy, society andenvironment.After summarized current situation and trend of water sources crisis in Northwest arid area, thispaper pointed out sharply that the reason retrograding on the function and impact of ecosystem and aggravatingthe water resources crisis is because human grabbed the water resources which belonged to natural vegetation andother living things, and the re distribution is unfair and unrational. It is one of reasons to lead more and morecritical water resources crisis that ecological water has been chronically ignored in Northwest arid area. Therefore, the paper firstly clarified the concept of ecological water, and proposed the follow its application tactics inNorthwest arid area : (l) to give priority to the ecological water in economic development and sustainable develop-ment, although industry, agriculture and municipality are all short of water in Northwest arid area. (2) to replenish the water to natural vegetation, especially arid grasslands and desert grasslands on the strips of desert andoasis plain with aritificial rainfall; (3) to rely mainly on channelling water to irrigate the artificial vegetation; andfor natural vegetation to irrigate by flooding. (4) to re distribute the water resources to oasis with after production water; and to treat and reused the pulluted water. (5) to bring the dominant of the corridors into full fuction, to establish the green corridors of combining tree with shrub and herbage. (6) to change the traditional irrigative pattern, and to devote major efforts to developing economic irrigation; (7) to harmonize relation amongecological water, production water and living water. This paper put ecological water on an equal pogition withproduction water and living water, which expect people to change the traditional idea of looking down on ecological water. It is urgently needed to organze multiple discipline research for new strategy of ecological water, inorder to make scientific management of water sources and the sustainable development of economy, society andenvironment in Northwest arid area.

Key words: Ecological water, Northwest arid area, Application tactics