This paper proposes a "non-contact virtual clay modeling system." We developed a prototype of three-dimensional modeling system that allows users to shape "virtual clay" with their hand movements. In our proposed method, the users? hand movements are observed with multiple cameras to estimate their positions. The human hand surface and virtual clay are modeled by using subdivision surface. Using these estimated hand positions, virtual clay is shaped based on a direct free-form deformation technique. To improve processing speed, we implemented the proposed system on a PC cluster. This system proves the feasibility of an intuitive virtual clay modeling system.