Recently, some modeling tools for generation of 3D-GC have been proposed. In these methods, we have to generate 3D models using a 2D input device such as mouse in 2D space projected from 3D space or orthographic views. In this paper, we attempt to construct a 3D-CG modeling tool by a marker which can input position and direction in 3D space, using ARToolKit for Augmented Reality. By this modeling tool, we can generate 3D-CG modes in 3D space directly. Therefore, we expect that we can intuitively generate 3D-CG models comparing with conventional 3D-CG modeling tools.