Irrational land use is the major force of the severe soil erosion and loss occurred in the Loess Plateau.Taking Majiagou catchment in Ansai county as an example,the characteristics and trends of land use/cover change were analyzed based on the first national land use survey maps in 1990(obtained from the Bureau of Landuse Survery of Ansai County)and the 2008land use map(mapped by field survey).In Arc-GIS,two types of land use maps were overlaid and the dynamic changes were analyzed.The results show that,from 1990to 2008,farmland and grassland decreased by 11.88%and 1.58% of the total area of the catchment,respectively.At the same time,forest,orchard and residential lands increased by 11.61%, 1.73%and 0.01%of the catchment area,respectively.The areal ratio of farmland,forest and grassland was changed from 3:1:6to 2:2:6during this period.The major transferring patterns among the land use system are grassland to forest,farmland to grassland,farmland to forest,and farm-land to orchard.Forest,orchard and farmland have relatively high changing rates of 8.06%,2.41%,-2.43%,respectively.Although the forestry area has increased over the past20years,it remains as an artificial ecosystem with the nature of instability and non-sustainability.The deployment of the national policy of“Grain for Green”since 1999and the substitution of farmers'operating strategies can be contributed to the increase of forest and orchard areas in the studied region.