Abstract: The design of wetland ecosystem is the key, fundament in wetland restoration, mitigation. In recent years, it has been frequently applied to the proper construction of wetlands. The paper first reviews the concept of wetland ecosystem design, as well as the basis of ecological engineering,, then presented the basic principles in the design of wetland ecosystem .Some major ecological indicators including hydrology, chemical, substrate, soil, biotic indicatiors were also discussed,and some reference values for ecological indicators were presented.On the base of the designing purposes,three major types in the wetland design were analysed. They include constructing wetlands for wastewater treatment, for mitigation wetlands,, for controlling flooding, non-point source pollution.