Abstract: Based on the color aerial photo and the field survey data, this paper analyze the information of various land use type change and spatial characteristics in Yanan Ecological Construction Demonstration Area from 2000 to 2003 by RS, GIS and statistics methods. We introduce the de-farming index and the de-farming Elasticity coefficient for the first time to evaluate the intensity, scale and spatial diversity of converting slope farmland into forestry and grassland, and to find out the range and pace of various land use type. This research illuminates the relationship between regional land use change and the project of converting slope farmland into forestry and grassland, and this research can give scientific suggestion to research on regional soil and water conservation and sustainable land use