[Objective] The ecological vulnerability of Wan'an county, Jiangxi Province, was quantitatively studied in order to provide a reference for the quantitative evaluation of land vulnerability at county level, so as to promote the sustainable development of social-economy-ecological environment.[Methods] The paper took Wan'an county, Jiangxi Province, as study area, to construct natural ecosystem vulnerability assessment model using the entropy and gray correlation analysis methods from three aspects, i.e., ecological supporting pressure, ecosystem sensitivity and ecological resilience, in accordance with the "pressure-state-response" assessment framework. Landscape fractal dimension, fragmentation, dominance, landscape adaptability index, human disturbance intensity, vegetation cover, topographic index and landscape type indexes and data of remote sensing of 1987,1995 and 2015 were used. The ecological vulnerability of Wan'an County was analyzed and assessed dynamically based on grid scale.[Results] The results showed that the land ecological vulnerability was exacerbated increasingly in 1987-2015 and 68.72% of our research area was in an increased ecological vulnerability. The distribution and trend map of land ecological vulnerability showed that high value areas of ecological vulnerability were concentrated in the central and the northern regions, while low value areas were concentrated in the south and the northwest. Method of spatial analysis were applied to analyze spatial cluster characteristics and the significance of ecological vulnerability. The spatial autocorrelation analysis revealed that the landscape vulnerability had high and increased spatial autocorrelation in 1987-2015. The main driving factors of ecological vulnerability in Wan'an County were per capita net income, the amount of fertilizer of per unit cultivated area and non-agricultural population proportion.[Conclusion] The ecological environment of the study area was severe. It was necessary to plan for rational land use and arrange the ecological functional areas according to the conditions in resources, climate, terrain and soil of Wan'an County.