Abstract: Diagnosis of obstacles for ecological security is a kind of complicated work. Based on RS and GIS, using the Grid technique, this article introduced the concept of factor contributing rate, degree of index departure and obstacle degree to assess the influence factors of ecological security in Jilin Province in 2000. Results showed that difference influenced factors in different area is so obvious. The region affected by one obstacle factor account for 76.92 percent of whole area.，among which, the degree of economic development, soil type, regional exploitation index, physiognomy，population increasing rate and comparative undulation are main factors. Two obstacle factors predominated besides one obstacle factor. The area of soil type affected is 27.57 percent of all study area and sand soil and salinized soil occupied more than three of four. We can see that sandilized and salinization have been ecological problems that can’t be ignored in Jilin Province. This study desertification the obstacle factors and offered a useful and exercisable data support for landuse regulation and regionally integrated father. The mothed that applied in the article provided a new view point for the diagnosis study of ecological security.