Ecological security is the needed state that different hierarchy or type of ecological systems to keep its normal configuration and function and gratify sustainable development for human in some period of time.It's the key part and base for agricultural sustainable development.The danger of environmental retrogression is kept on guard highly in China.The study of ecological security is becoming the major foreland and task in geography,ecology,and resource and environment science.Taking counties as basic unit,under the technique of AHP and GIS,based on the analyses of the compressive stress of the agricultural eco-security system and the set eco-security evaluation index system through pressure and quality of resource-environment and protection and renovation of resource-environment,integrative evaluating on the agricultural eco-security of counties in Dongting Lake area is made by "agricultural eco-insecurity exponent".The result indicates,agricultural eco-security of Dongting Lake area has been confronted with a series of problems and challenges,such as the descending of the accommodation function of the lake,the more and more serious of water loss and soil erosion and flood disaster,three wastes of small and medium sized cities,agriculture and heavy metals generating pollution and so on.And the regional heterogeneity of the security degree is distinct.The agricultural eco-insecurity exponent is getting smaller from near the lake to far away from it.The research achievements can be used as science-dependencies for maintaining the agricultural eco-security in Hunan province directly,and its research technique can be used for reference in regional agricultural eco-security evaluation.