Abstract: The Southern Part of Tarim Basin is the area Where the south route of Silk Road got through. In ancient times, this area once had been quite Prosperous, but late it deteriorated to desertified lands, which resuited from the special local natural conditions(such as the extreme conditions of dry climate, the widespread and loose deposition, the removal of rivers and so on) and social factors(such as chaos and wars, etc). The processes of desertif ication were developing quickly during-the Han-Jin Dynasty, the Tang Dynasty(especially in the later period), the song Dynasty and Yuan Dynasty.