Abstract: The southern part of the Tarim Basin is the most fragile eec-environment area in China. According to the archeological data, history references and paleoclimate information, its eco-environment has taken great changes during the recent 2000 years, which are characterized by the evolution and desertification of oasis and lead to many famous ancient cities having been abandoned and the south' silk road' has been moved southward. This paper analyses distribution and evolution of oasis, outlines the natural and man-made causes for the changes. The results show that oasis environmental changes are due to the aridization of climate before 20th century but mainly attribute to the human activities after into the 20th century. In order to prevent its eec-environment from further damaging, some adaptive measures should be taken timely: ① to develop and utilize water and soil resources rationally; ② to regulate the structure of agriculture; ③ to develop some preponderant resources such as solar and wind; ④ to protect natural oasis effectively.

Key words: southern part of Tarim Basin, oasis evolution, environmental changes, natural factors, human activity