Based on multi-spatial information, analytic hierarchy process(AHP), principal component analysis and grid GIS technology are applied in gridding the indicators of ecological vulnerability evaluation system at 10 m×10 m scale and achieving the spatial data about the ecological vulnerability of grassland in Changshun County, Guizhou Province. The ecological vulnerability of karst grassland is divided into 5 levels according to ecological vulnerability index(EVI). The analysis shows that the area of heavy vulnerability region is 36.32 km², taking the largest proportion; the areas of moderate and extreme vulnerability regions are 28.09 km² and 24.99 km², respectively; and the areas of slight and potential vulnerability regions are 16.54 and 8.60 km², respectively, taking smaller proportions. Overall, the ecological vulnerability of grassland in Changshun County is at a higher level and the ecological vulnerability of karst grassland is resulted from the special geological background and frequent human activity interference.