Methods and categorical model for extracting factors affecting soil erosion potentiality with the aid of remote sensing and geographical information system were explored. Eight factors such as slope, rainfall eroding force, vegetation coverage, soil layer thickness, population-environmental capability, soil erosibility, lithology and percentage of cultivated slopeland to slopeland were used for assessing soil erosion potentiality. The modified AHP method was used to determine the weight of each factor. And the soils in Qingdao were graded and evaluated in terms of soil erosion potentiality, using Software ARCGIS and ARCVIEW.