Using “3S” technology, the authors carried out research on the changes of the wetland landscape pattern of the

green corridor in the lower reaches of the Qarqan River based on the diversity index, dominance index, fragment index and

patch shaped index from 1975 to 2007. Some conclusions have been reached: the wetland area and patch amount increased a

little from 1975 to 2000 and decreased greatly from 2000 to 2007. In the past 32 years, the average area of the patch and

the patch density have been reduced continuously, and the patch shape turned to complex； the diversity of the landscape

pattern decreased, but the dominance and the fragmentation increased； in all the wetland types, the change range of the

river wetland area was small, the lake wetland area increased greatly, and the marsh wetland area decreased considerably.

The variation of the wetland landscape aggravated the sandy desertification and led to the reduction of biodiversity, but

it guaranteed agricultural water demands and ecological water demands, which would be favorable to the stability of the

Qarqan River green corridor ecosystem.