Orthopedic splint is composed by manifold layers of orthopedic casting tapes and specially non woven fabrics. It is characterized by better viscosity, fast drying time, high rigidness after dying and light weight. Due to better bio compatibility, polyurethane is widely used in medical places. Animal study and acute and chronic toxicity test have proved that medical polyurethane was non-toxic and no-induced distortion, no local irritation and no allergic reaction.