Most lakes in Xinjiang Province have been shrinking considerably since the 1950s, especially in plain and desert areas, and some have even dried up.The lake shrinkage took place on account of large-scale reclamation, and was an inevitable outcome of the economic development and the expansion of irrigation areas in arid and semi-arid lands.The reasons are as follows: (1) The population increase and economic development require the expansion of cultivated area.(2) The distribution of arable lands determines water resources utilization.(3) It is troublesome to balance the expansion of irrigation area and the maintenance of lake area simultaneously because of limited water resources and lake locations.That whether the eco-environmeat of the whole watershed is ameliorated and the regional productive power is improved should be regarded as the standard to evaluate the effects of lake..shrinkage mentioned above.Many reservoirs have been built in the upstream area of lakes as the lakes shrinked or dried-up downstream.Large-scale irrigation and afforestation have alleviated the local cb'mate, especially in oasis areas.The ratio of water resources utilization is greatly improved by constructing water projects.The oasis areas are expanded more rapidly than the losses of desertation as the productivity of oasis areas steadly grows.Human powers to prevent and mitigate natural disasters (such as flood and drought) have been strengthened in almost every watershed of Xinjiang Province.The sustainable and stable growth of agriculture has promoted the economy and provided a favorable basis for further development.It is necessary and possible to protect the existing lakes in plain areas.The fate of them depends not only upon natural conditions and evolutions, but also upon the need of economic development.Consequently, the utilization and conservation of lake resources should take the eco-environmental factors as well as economic ones into consideration.