[Objective] Studying the dynamic change of desertification in Dunhuang City in order to provide a support for desertification prevention and cultural relics protection. [Methods] Based on the remote sensing data and geographic information system, the TM and ETM images were determined by field investigation and man-machine interactive interpretation. Aerial land desertification information of Dunhuang City from 2004 to 2009 were extracted. [Results] There were 1.97×10⁶ hm² desertification land in the whole city, covered 73.8% of the total land area. The total desertification land was reduced about 9 102.59 hm² during the study period, the annual decrease ratio is -0.001%.Very severe desertification lands reversed to severe, moderate and light desertification land. The desertification was alleviated largely. [Conclusion] Vegetation coverage is improved in the study area, which made the desertification slowed down and reversed, but desertification had not been fundamentally changed, desertification prevention will still be a long-term task for Dunhuang City.