The regionalization of soil and water conservation in Jiangsu Province is to make up for the deficiencies of the third level of national regionalization in Jiangsu Province and thus to manage soil and water conservation in the province more efficiently. This paper builds the index system of regionalization in accordance with the characteristics of Jiangsu Province, simplifies the factors' indexes by principal component analysis method, and draws, with the aid of GIS software, the distribution maps of the four major factors, namely nature, economy and society, land use, and soil and water loss. In the maps, the analytic hierarchy process(AHP) is employed to get the weight of each factor, and the conditional raster image overlay method is used to complete the superposition of the four factors with GIS software. The resulted raster images are reclassified and thus the quantitative division of soil and water conservation in Jiangsu Province is finished. This method can improve the efficiency and accuracy of the regionalization of soil and water conservation in Jiangsu Province and make up for the deficiency of subjectivity in the current regionalization.