Abstract: In this paper, the holistic landscape pattern and its spatial difference in the mainstream area of the Tarim River in Xinjiang were analyzed based on GIS and quantitative analysis. According to the physical geographical features in the drainage basin, 35 buffer zones were delimited along the transversal gradient of 5 river sections, Fragstats was used to select the landscape indexes at both landscape level and landscape type level, and the landscape pattern gradients were analyzed and compared. The results were as follows: (1) The area of natural vegetation occupied 35.1% of the total landscape area, and that of other land use types occupied 54.88%, so the latter was the background of landscapes in the drainage basin. The area of lowcoverage grassland in a continuous distribution trend was the largest, that of highcoverage grassland was spatially distributed in an aggregated way, the patches of forestland were small and were separated by other landscapes, the patch number of farmland was the most, and the landscape diversity and landscape heterogeneity were decreased from the upper reaches to the lower reaches of the Tarim River; (2) Heterogeneity of the spatial pattern of land use was significantly high, showing a gradient pattern with geographical gradient and buffer zone, the river corridor change was the driving power resulting in the variation of landscape patterns, the corridor widths of the Tarim River was 8.6-10 km, 6.6-8.1 km, 4.8-4.9 km and 1.4-5 km along the river section 1, 2, 3 and 4 respectively. The change trend of the indexes with the change of buffer zone width could be used to reflect the intensity of potamic effect; (3) At the landscape type level, the landscape indices reflected the sensitivity degree of different landscape types to the potamic effect, the forestland was mainly distributed in a corridor width of 1-5 km, the sparse forestland in 1-10 km, the highcoverage grassland in 1-9 km, and the lowcoverage grassland in 1-12 km. An analysis method of landscape pattern in buffer zone was developed, and it was used to reveal the dynamic trend of landscape gradient and the extent of ecological benefits in the river corridoroasisdesert ecotone so as to formulate more effective development policy and provide a reliable basis for regenerating the degenerated ecology.

Key words: landscape pattern, buffer zone, gradient variation, landscape index, mainstream of the Tarim River