Sanjiang Plain is one of the biggest centralized distributing area of wetlands in China. As a result of fifty-year large-scale reclamation, the area of wetlands decreases rapidly while that of the cultivated land increases greatly, the area of natural wetland decreased from 5340000 ha in 1949 to 1130000 ha in 2000, only accounting for 10.39% of the whole area . Due to the fragmentation of wetland itself, it is confronted with shortage of water source, and is becoming isolated islands. At the same time, the degradation of wetland function is also serious,such as the decrease of the species richness of wetland plants, the reduction of the bio-productivity, the increase of the species number of endangered plants, the annual decrease of the number of endangered animals, especially rare waterfowl. The reclamation of wetland resource has a certain impact on regional environment, such as the aggravation of soil erosion, the increase of the content of soil granules, the evident decline of soil fertility, even the occurrence of desertification locally, the rise of temperature,reduction of precipitation and the increase of drought occurrence frequency.In order to reverse this situation, the conservation engineering progects of wetlands must be implemented, including irrigation project, habitat corridor construction project and showing care for wetland project.