Abstract: Point cloud data is a popular representation of object shape information. Triangulation of scanned point data is an important means for 3d surface reconstruction. In this paper, a new interpolation method is introduced to reconstruct object surface automatically from unorganized point cloud. Our proposed method generates some accurate interpolation points to make the results more reliable based on 3d Delaunay triangular mesh. Each center of the 3d Delaunay triangles is mapped onto the tangent plane of the three vertexes of the triangle, and further accurate interpolation points (also called growing points) are acquired by simplifying the mapping points. Triangulation by a mixture of the growing points and original point cloud data could make the triangular mesh reconstruction of the object more realistic and retaining more detailed information. Experimental results display that our method is effective and robust.