Abstract: A region-growing algorithm is proposed to reconstruct triangular meshes from unorganized point cloud. The algorithm firstly computed the neighborhood smoothness of each point and constructed an initial seed triangle in the smooth region; then the active edge from the smooth region is chosen to grow according to priority and the neighborhood smoothness is introduced to select the satisfied candidate point for constructing a new triangle in each growing; finally, a manifold mesh is constructed by a post process. Experimental results show that the proposed algorithm can reduce the possibility of making topological and geometric errors by fully considering the smoothness of each point's neighborhood and preserve the sharp edge of the underlying-object naturally.