This paper proposes a new cloth design system that provides intuitive operations, e.g., sewing, cutting and fitting a cloth in a virtual 3D space through direct manipulations using a force-feedback device. Advances of computer hardware technologies and results of virtual reality researches make it possible to develop virtual reality applications those provide an immersive environment where the user manipulates 3D objects as if he/she existed in the real world. A lot of cloth simulation algorithms and systems have been proposed and existed so far. However, there is no cloth design system that provides intuitive operations enable the user to sew, cut and fit a cloth in a virtual 3D space as if he/she existed in the real world. So, the authors developed such a cloth design system. This paper describes what kind of model is employed for the cloth simulation, what kinds of operations are implemented, and quantitative performances of the system.