Abstract: The Assessment of Erosion Using GIS ARC View. The social activities in watershed area, should be taken in to account in order to keep land conservation.  Land conservation at sub watershed of Coban Rondo upstream is very important because can result erosion and sedimentation in Selorejo Dam.  Assessment of erosion using Arc. View GIS is beneficial in calculating the level of erosion, because it can determine quantity and distribution the erosion level. The level of erosion at Sub watershed of Coban Rondo vary from permission level as large as the area of 6.457 ha has to critical level as large the area of 158,775 ha, and the very extrem level of was not found.