The land degradation is very serious in the west of Northeast China, and saline-alkali landscape accounts for the high figure of degradation. Taking the Da'an County as an example, based on relief map, TM and MSS data, changes and causes of saline-alkali landscape were analyzed in quantity type, and spatial distribution. Results show that the area of saline-alkali land in Da'an County had been increased 74146 ha during 1956-2000. In the process of land use change, the conversion rate between grassland and saline-alkali is on the topmost. Because there were spatial differences existing in saline-alkali land's transformation, from 1956 to 2000, the gravity center of saline-alkali land had moved 18.19km towards the southwest. The increased saline-alkali land resulted from both the effect of natural and human factors. The southern part is more sensitive to climate, while human activity played an important role in the evolution of saline-alkati land in northwest region. Trend analysis based on Simile model was done to predict the change of saline-alkali land in the future 100 years given that the physical and human influenced factors wound not been changed, with the objective of developing adaptive strategies for sustainable development of the land.
