Abstract: The west Jilin Province is located in the transition zone from semi-humid climate to semi-arid climate with many types of ecological landscapes and is a typical area between agriculture and husbandry. Since the 1980's, the land use/cover in this area have undergone dramatic changes. Under the pressure of population growth and excessive land exploitation, such as over grazing and over reclamation, the ecological environments that have been fragile become more vulnerable and unstable. On the basis of systematical analysis on the natural and artificial factors and their relations influencing environment evolution, the leading factors of eco-environment degradation are extracted qualitatively in this area. Under the GIS technology, digital environmental model is established. Using 100m?100m real area as basic unit, the spatial principal components analysis method is applied to calculate the eco-environment synthesis exponent according to the weight of some indexes. The eco-environment vulnerability index (EVI) is produced to evaluate the eco-environment fragile status during 1986-2000. Results show that the eco-environment quality gradually declines from the central to peripheral. The fragile status of some areas in the south sand land region, the central alluvial plain region and the north floodplain region has been exacerbated remarkably in recent 15 years.