The entironment problem of Talimu Basin have been regarded highly. Many experts and scholars had investigated and researched the Talimu Basin. In the basin

there are 5 reservoirs. They intercepted large number of supplied waterhead. In this background

we began this research. This article introduces a kind of method. This method is to syntheticallly use RS

GIS and GPS（3S）technology and retrieve remote sensing information according to time sequence about land use/cover

Ⅵ（vegetation index）

and population economy etc. in the middle and lower reaches of Talimu River. In this article

the data were analyzed by using GIS technology and the field sizes were investigated by using GPS instrument. A conclusion was concluded that in the past 11 years from 1990 to 2000

in the region of the middle and lower reaches of Talimu river

the area of farmland had been increased 505.433km 2

the area of nature/planted vegetation had been reduced 943.089km 2

and the area of water body had been increased 80.477km 2. The area of desert of the middle and lower reaches of Talimu river is increasing continually. The main reason is the large number of nature vegetation was died

especially the area of the Huyang trees was declined. Finally

some suggestions were make to recover and father fragile ecosystem.