Abstract: Mesh segmentation is important for many geometry processing applications including mesh parameterization and texture atlas generation.This paper presents a new and efficient algorithm for mesh segmentation based on the convex-concave analysis for vertices or faces.The convex-concave analysis based on the uniform supporting radius divides the vertex into four categories:flat vertex,convex vertex,concave vertex and feature vertex.The algorithm firstly performs the planar region growing from the flat vertex,followed by the convex-concave region growing from the unclassified convex or concave vertices and finally by the competitive region growing according to the smoothness of border vertices and border edges.For the mesh models which are not segmented fully,the algorithm takes the similar steps based on the face convex-concave analysis to complete final segmentation.This algorithm is fast in mesh segmentation while preserving geometric features,and is particularly suitable for CAD model segmentation.