Abstract: Yinbazha district is located in the middle stream of Tarim river with such characters as extreme drought,salinization,strong wind-sand,soil of light texture,sparse plant and desertification.Basis on the existing and a great deal of data surveyed on the field,this paper studies the relationship between the desertification and the important environmental factors. Results of the studies show that the factors obviously to impact on the formation and improvement of desertification in the region of Yingbazha are underground water level,plant, micro-geomorphy,and soil texture in turn.Plant situation plays an important role in restraining the formation and improvement of the desertfication.The relationship between the middle value of the plant coverage and the desertification degree can be described as follow： Y=0.428-0.078X.The general regulation of the change of desertification with the change of the underground water level are：（1）With the increment of the desertification degree,the scale of underground water level is from the wide to narrow;（2）The underground water level of the emergence of every desertification is from the shallow to the deep.The relationship between the mean quantity of underground water level and the desertification degree is： Y=4.258-0.778X.Although the strongest desertification can be formed on the condition of underground water level of 4 m ,on the other hand the non-desertification also can be formed on the condition of underground water level of 9 m ,which only shows that underground water level does not obviously influence on the desertification in short time because of the course change of Tarim river,the underground water level of 4.4 m is suitable to maintain the ecological environment in general and in a long term on the basis of desertification study.Results of the studies provide the basis for improving the operationablity of ecological environment conservation in the basin of Tarim.

Key words: Tarim river, Desertification Ecological environment Conservation