Abstract: In recent decades, the ecological environment of Songnen Plain had deteriorated severely and the desertification in Songnen Plain expanded rapidly, which is related to the durative descending of territorial function of water and soil conservation.　Applying the theories of bionomics, economics, environmental science and the technology of 3S, a multiple computation model for water and soil conservation value in Songnen Plain is put forward based on DEM and TM/MODIS data. The calculation results indicate that the water and soil conservation value was 6.626 3×10¹⁰Yuan RMB in 2001 in Songnen Plain. The water and soil conservation value per unit area in forest was the highest with the value of 1.735 9×10⁶ Yuan per km² and the grassland and the cropland was 7.04×10⁵ Yuan per km2, 2.453×10⁵ Yuan per km² repectively. The land that was difficult to use had a value of 2.89×10⁴ Yuan per km². The water soil conservation value tended to be digressive from northeast to southwest in spatial distribution. The water and soil conservation value was descending from 1.938 6×10⁶ Yuan to 1.887×10⁵ Yuan per km². These results indicated that the key to heighten the function of territorial water and soil conservation is to enhance the ecoconstruction for forest and grassland, and it should strengthen the water and soil conservation work especially in middle and western area of Songnen Plain. The trial to quantitatively evaluate the water and soil conservation will supply a basic data for green GDP accounting.

Key words: Songnen Plain, water and soil conservation value, multiple computation model, land use type, TM/MODIS/DEM data