Based on the techniques of GIS/RS and the methods of the landscape ecology, the characteristics of the landscape changes and driving forces in midstream of Heihe mainstream basin from 1985 to 2005 were analyzed in the paper, especially the changes of landscape after water redistribution scheme in Heihe River basin was executed. The results showed as follows: (a) The landscape had changed greatly in Heihe River basin from 1985 to 2000, the farmland, woodland, resident and industry land increased, while grassland, water area and unused land decreased; the farmland, resident and industry land continued to increase from 2000 to 2005, and the changes of other patch type was adverse. (b) After 2000, at the class level, farmland and resident and industry land have become more fragmented, along with the area increasing, and patch shape has tended to be more regular, and the spatial connectedness of these two types increased gradually. The fragmentation, spatial connectedness and landscape dominance of woodland, grassland, water area and unused land had similar change trends. The fragmentation increased, but the spatial connectedness and landscape dominance of these four types decreased respectively. (c) At the landscape level, the diversity, heterogeneity and fragmentation of landscape increased after 2000, while the spatial connectedness and landscape dominance decreased. (d) The main forces of landscape change included population growing and the economic development. However, the reduce of available water resources in Heihe River has become the main force since 2000 which caused the significant changes of the landscape change.