land degradation is considered as potential or actual production loss as a result of natural or human factors. In this study, a monitoring system was used for mapping land degradation at a regional scale (Isfahan province) which uses four indices including vegetation cover, rain use efficiency (RUE), surface runoff and soil erosion.Vegetation was estimated using 16-day data of Normalized Difference Vegetation Index (NDVI) of MODIS sensor (MOD13A2) and rain use efficiency was estimated by the ratio between Net Primary Productions () acquired from MODIS sensor data (MOD17A3) to annual rainfall. Surface runoff was estimated based on Soil Conservation Service (SCS) of America model using precipitation, vegetation, land cover and soil data. Soil erosion, as one of the most important features of land degradation was modeled and calculated using surface flow, vegetation, soil digital maps and digital elevation model (DEM). Then the 4 indicators were combined to identify the areas with the highest degradation potential in Isfahan province. The results showed that, given that each indicator is of particular importance in the description of land degradation, it is worth while to combine the vegetation, rainfall use efficiency, runoff and erosion factors to determine the areas in which the degradation takes place.The results showed that areas with low degradation risk were distributed through out the province and covered about 10% of the province, also areas with medium degradation risk comprised most of the province area (about 88%). The highest degradation was observed in the western part of the province (Fereydunshahr county) covering that about 2% of the study area. This region is characterized by Zagros Mountains with high rainfall. The vegetation in this area is almost in good condition but the extreme exploitation of the vegetation and also due to steep slopes in the region has reduced the ability of vegetation to conserve soil from erosion Overall. The results of this study showed that remote sensing technology can be used as an effective tool in land degradation assessment and monitoring. The reason is that it can provide calibrated, objective, repeatable and cost-effective information for broad regions. Therefore, the satellite- derived four- factor method used in this study has high capability in land degradation studies and can be applied to other similar arid and semi-aid environments. Keywords : land degradation, RUE, MODIS, NDVI,, Isfahan