随着长江流域社会经济发展和城镇化进程加快，由水污染引发的水质型缺水问题日益突出，为此介绍了长江流域城市污水处理现状，分析了城市污水处理中的节水效应，并就如何提高城市污水处理能力，促进城市节水提出了一些建议。同时指出：流域今后节水应加强两方面的工作，一是加快城市污水处理设施的建设，提高污水处理率，改善近岸水域水质状况，逐步消除沿岸城市水质型缺水危机；二是使污水处理厂走污水资源化的道路，提高污水回用率，节约宝贵的淡水资源，缓解缺水城市的供水矛盾。

With socioeconomic development and rapid urbanization, the water shortage due to contamination of water quality becomes more and more severe in Yangtze River Basin. So, the authors introduces the present situation of city sewage treatment and analyze the water saving effect of city sewage treatment. Finally, two kinds of water saving measures are concluded as follows: One is to enhance urban sewage treatment rate by building more sewage drainage works to solve the problem of water shortage owing to water pollution；the other is to upgrade reuse rate by adopting advanced city sewage treatment plant to save valuable fresh water resources.