Abstract: In the automatic river generalization, a double line river need to be transformed into a single line river sometimes. An improved algorithm is given to solve this problem. First, the medial axis of a double line river is extracted based on Delaunay triangulations, and the double line river is splited to segments by its skeleton. Then, spatial graphic conflicts are detected by means of buffers of the small\|scale segments’ skeletons. At last, the spatial graphic conflicts will be solved and the generalization result will be corrected.