Based on the TM image of Wuwei and Minqin oases in middle and lower reaches of Shiyang rivver in 1986 and 2000. Using GIS technique and landscape structure analysis program FRAGSTATES. It calculated and analyzed the landscape metrics and their changes of studying regiong at class metrics level and landscape metrics level respectively. And also the changes of land use patterns in two oases were compared by caculatin transforma- tion matrixes of landscape mosaics.