CAD system is useful to define and input any artificial 3-dimensional configuration into computer, but the input of arbitrary natural 3-dimensional configuration is still serious for computer users. This paper includes a method to input arbitrary 3-dimensional configuration into computer. The method is based on 3-dimensioanl Delaunay triangulation which is a geometrical subdivision of arbitrary 3-dimensional convex domain into tetrahedra, and the auther shows a method to find triangles which cover whole surface of 3-dimensional body using the result of Delaunay triangulation.