Three temporal remote sensing images were used as the main sources of information. The images were processed in combination with field investigation. The results show that soil salinization of the land area had increased from 1973 to 1990，and then declined from 1990 to 2005； the extent of land salinization had increased from 1973 to 1990，and then decreased from 1990 to 2005. Land salinization is distributed around the low-lying areas of the Kaidu River, lakesides and Qingshui Drainage，Quhui Drainage and Wushitala Drainage on the north of the Bosten Lake. The land salinization was closely related to topography, groundwater and arid climatic conditions. Human agricultural activities have also played an important role in soil salinization.