To realize the stereo matching of natural scene contour edge,a fast matching algorithm based on region adjacency graph was proposed.Firstly,on the basis of image segmentation by using the watershed transformation method,the contour edges were detected according to the boundaries of the segmented regions.Then the matching process was divided into two steps based on the global-to-local hierarchical matching idea.The first step was region edge matching by grouping the contour edges according to their corresponding regions.After establishing the region constraint based on the region characteristic,the region edge matching was accomplished in the guidance of corners in a similar way of region growing.The region constraint reduced the search area and optimized the matching order effectively.The second step was edge point matching.By using the matched corners as datum marks,the edge constraint established in the first step could limit the search area in several pixels.Experimental results show that the proposed algorithm can acquire high correct matching ratio and fast matching speed.