1. College of Geo-exploration Science and Technology, Jilin University, Changchun 130026, China;
2. College of Earth Sciences, Jilin University, Changchun 130026, China;
3. College of Surveying and Prospecting Engineering, Jilin Jianzhu University, Changchun 130018, China

Based on remote sensing and GIS technologies, the data of MSS imageries in 1975, TM imageries in 2000 and ETM imageries in 2015 is used to obtain the spatial distribution data of Sanjiang plain wetland by visual interpretation and supplementing field survey verification. Further study on the distribution features from 1975 to 2015 is carried out. Combined with the data of climate and precipitation, the authors analyze the influencing factors of wetland variation. The results show that before 2000, the total area of wetland reduced 8 426.81 km², of which the swamp meadow wetland reduced most obviously, while the constructed wetland increased 6 939.87 km². After 2000, the swamp meadow wetland dramatically reduced 2 794.24 km², and the constructed wetland kept increasing. The landscape fragmentation of natural wetland increased, indicating that wetland distribution features were mainly influenced by human activities.