Abstract:The mechanism of interaction between land use change and landscape pattern have been regarded as the research pivot in the field of global environment change. The quantitative evaluation on land use change as well as the influence of which on landscape pattern caused by land exploitation and reorganization at a large scale is significant to the sustainable utilization of local land resources. The objective of this research is to evaluate the influence of land use change on the landscape pattern of a typical watershed in the arid area at a long time scale, which could provide useful information for making decisions on economical development and environmental protection. The study area in this research, the Manas River Watershed in Xinjiang, belongs to a typical area with dramatic exploitation and use of water and land resources in the arid area of the northwestern of China. Required data consist of topographic maps in 1962 and remote sensing images taken in 1976, 1989, 1999 and 2008. Based on these data, we use mathematical models and index of landscape pattern to rebuild the process of changes in land use and landscape pattern, and analyze the influence of land use change on the landscape pattern. The results show that: (1) the land use in Manas River Watershed changed dramatically in the recent 50 years. Cropland and built-up land obviously increased with the trend and status index of 0.83 and 0.81, respectively. The unused land and woodland presented decreasing trends with the trend and status index of -0.67 and -0.51. However, the grassland and water decreased following an increase, the trend and status index of which is 0.2 and 0.45, respectively. In the study period, the comprehensive trend index is 0.55, and the land use change was overall in unbalanced status dominated by one-way transition. (2) The fragment and diversity of the landscape increased in the study area, and the fragment index increased from 0.2×10-6 in 1962 to 0.116×10-4 in 2008, the diversity increased from 12568 in 1962 to 1.4358 in 2008. Both the heterogeneity and the complexity of the landscape experienced an increase during this period. In contrast, the dominance decreased from 0.5350 of 1962 to 0.3559 of 2008. (3) The land use change drives the landscape pattern of the watershed developing towards diversity and fragmental structure. As a conclusion, developing intensive agriculture reduced the negatively ecological effects on landscape pattern evoked by land use changes.