Abstract: The ecological system of the oasis in the tw0 river bains having been affected by the unseasonable artificial activities for 30 years, became worse and worse.
1. The forest on the desert has decreased 1.8 million mu in number (49.34% reduced )，shrubbery have been 65% decreased. These turned more area into desert.
2. The secondary salinized soil amounts to 53.03% of the total. The nutrient of the farmland is in imbalance, fertility is decreased and only 0.845-0.90% of the organic matter is contained in the cu1tivatable layer of soil.
3. Grassland is overladen by herding and caused serious degeneration. During the recent 9 years, 409,000 mu grazing-land have been damaged by digging licorice root. The area of grassland has been reduced by 50%.
In recent years, the ecological system of the oasis is gradually becoming recovered. The main measures in arid-desert area are to build complete oasis and to protect desert vegetations.