Abstract: The aims,principles and requirements of the water ecological planning for city environmental system are analyzed and the ways of water eco-structure designing for cities' environment are discussed in this paper.By applying the ecological theory and methods and studying planning of the eco-function and eco-analysis,the environmental water in cities is planned with the macroscopic and microcosmic view,on the basic of maintaining the balance and intactness of the eco-system on considering the geological locations,the different requirements of function,the different ways of applications,the different development potatials of the environment water.The structure designing of the eco-system makes the ecological functions and aims of environment water in cities come true and establisles a complete and sustainable water eco-system.