[Objective] To investigate the spatial distribution of saline alkali land in Manasi irrigation area, in order to understand the type and the spatial and temporal changes of local saline alkali land, and find out appropriate improvement measures.[Methods] Based on the soil data in 1985, Landsat TM images in 1998 and CBERS(China-Brazil earth resource satellite) images in 2006 and 2014, the RS and GIS technology was used to extract the information of soil salinization during four periods. The land transfer matrix was used to analyze the spatial-temporal changes of salt-affected land in Manasi irrigation region during the past 30 years.[Results] (1) The area of soil salinization land in Manasi irrigation region had increased from 4.27×10⁴ to 7.90×10⁴ hm² during the past 30 years. (2) Soil salinization was mainly distributed in the inner area of Manasi irrigation region, represented as a block pattern.[Conclusion] Nature factors are the internal causes of the formation and change of the soil salinization, and anthropogenic influence is one of the driving factors that promoting the development of soil salinization, especially for the secondary salinization of oasis.