The regional ecological risk has the characters of large scale, multiple stressors and multiple types of agents and difficult being quantified, From the definition of ecological risk, the ecological risk assessment method based on the indexes of landscape fragmentation degree and land value coefficient weighted by areas proportion has been put forward in this paper. Based on software platforms of ArcGIS and FRAGSTATS, the isoline map for ecological risk can be created by using the spatial sample method and the ordinary Kriging interpolator method. The land use map of Hohhot City for year 2005 was selected as example,the scope of ecological risk are between 0.04-0.26,but spatial difference of them are obviously, which high risk region locate at northeast mountainous area and southwest corner of faming land,. The driving force of north areas comes from soil erode, underwater and forest degradation, while that of south areas are the rapid industrialization,which make the forest, grass and especially agriculture land rapidly convert to industry use land. The results show the method set up in this paper is intuitionistic and convenient. It can be used to score relatively value and rules of spatial distribution for regional ecological risk.