Red soil is susceptible for soil erosion because of its intrinsic material components, and together with the eroded soil material. The plant nutrients are washed away, and the concentrations of nutrients are even higher in the sediment than in the topsoil of the former soil. From 1978 onwards, at the beginning of the period of opening and reforming, the farmers were assigned a piece of land and were encouraged to cut down the forest as a measure to increase local economy. All of these human activities further result in significant red soil erosion. An eight-band Landsat ETM data acquired in 2000, soil map, digital topographical maps with scale of 1:10 000 and field data were used to identify and map the eroded areas in the red soil region in Jiangxi province. The satellite image was calibrated, registered and georeferenced, and a supervised training technique based on areal extraction of spectral values, with spatial (topographical information) and spectral constraints was used to generate the spectral signatures of the informational classes. Ancillary data such as land use map from local government were used to assist the satellite image classification and interpretation. The results showed that low and very low erosion area accounted for 41.3% of the total study site, medium for 9.4%, high and very high for 37.7%, and no erosion area (water surface, etc.) for 11.6%. It also indicated that Landsat ETM supported by thematic GIS data can discriminate the soil erosion features in the red soil region in China.