Abstract: To provide some basis for the ecological environment management and protection of the ecotone in the southeast margin of the Qinghai-Tibet plateau, this paper selected nine evaluation indexes and adopted the method of entropy and AHP to evaluate the ecological environment vulnerability of the southeast edge of the Qinghai-Tibet plateau in 2010, 2015 and 2018 based on the data of meteorology, topography and land resources. The results showed that the vulnerable areas of the study area were in the decreased order of mild vulnerability, micro vulnerability, moderate vulnerability, severe vulnerability, extreme vulnerability; The vulnerability degree of the ecological environment in the study area was mainly affected by soil erosion, vegetation coverage, slope, land use type and temperature; The vulnerability degree of the ecological environment in the study area was distributed as decreased order of glaciers, glaciers and woodlands belt, forest grass ecotone, cultivated land, grassland, and forest land; Compared with 2010, the ecological environment in 2018 showed a positive trend of change. The results indicate that the ecological projects such as the restoration of alpine grassland and the conversion of cropland to forest have been effective in recent years, but still need to continue to promote and improve the means of environmental governance.

Key words: entropy method, analytic hierarchy process, the ecotone of the southeast margin of Qinghai-Tibet plateau, the fragility of ecological environment, the trend of change