On the bases of the TM of 1989 and ETM of 2001 images and the other necessary information, the images of the study area accurately were classified and the development and formation mechanism of soil salinization in the Delta Oasis of Weigan and Kuqa Rivers were studied. The results showed a deteriorating tendency of soil salinization in the region, the areas of medium and intensive salinization increased from 11.22% and 4.37% in 1989 to 17.68% and 5.17% in 2001; during this period human activities played a significantly negative role in the process of soil salinization, which heavily threatened the agricultural development of this region.