Abstract: The west of Jilin Province ever possessed plenty of water and grassland.In the past three decades,with the population explosion and overdevelopment of the natural resources,there are many environmental problems,such as water resource scarcity,and alkalized and sandy cultivated land,which restrain the environmentally sustainable development.Based on the extensive factors,the authors set up an evaluating index system and established the process of the quantitative assessment of fragile eco-environment.The process includes the set-up of a database,and the determination of assessment cells,assessment indicators as well as their weights,and assessment methods for fragile eco-environment.With powerful input,spatial analysis and mapping functions of GIS,and adopting the AHP method and the comprehensive index method,quantitative assessment and zoning are performed for fragile degrees of fragile eco-environment.