Abstract: Water body feature extraction from remotely sensed images can be easily affected by several factors such as topographic shadowing and habitation settlement place. In order to solve the precision problem in water body feature extraction based on SPOT5 images，this paper proposes a novel water body extraction approach.The proposed approach is based on the study of a water body’s remote sensing image background value. It is able to polarize water body gray values by constructing water body index that is able to enhance in the same direction and across multiple indices the integration calculation model.Based on these techniques，the proposed approach utilizes an automatic threshold selection algorithm，mathematic morphology filtering，and thinning algorithms to enable automatic water body featre extraction with high precision. The experimental results and corresponding comparisons show that the proposed approach is able to effectively extract small water bodies and remove top-ographic shadowing，habitation settlement places，and river alternative bars etc.