| As a case study of Tongyu county,Jilin Province,This paper established the indicator system of ecological security on agricultural sustainable development,determined the weight of the indicator by the method of mean square deviation,and evaluated ecological security on agricultural development among 1985, 1990,1995,1998,2001 and 2004 by using the model of ecological security.The result showed that the ecological security of agriculture had being decreased during the past 20 years,the grade of ecological security of Tongyu County of the above motioned 6 years was between III and V,and the security dropped from sensitive state to risk state.1998 was the turning point,from which the ecological security of agriculture had being recovered.The strategies of construction of ecological safety on agricultural sustainable development are put forward. |