A case of 35-year-man with a rhabdomyosarcoma in the mandible has been presented. Chief complaints are dull sensation and growing mass at the area of the right mandible. In order to make diagnosis, roentgenograms were taken which revealed some sort of radiopaque and punched appearane at the area from right body to angle of the mandible, and biopsy was made, by which rhabdomyosarcoma was observed. The author treated this patient in terms of hemimandiblectomy, neck dissection and resin-made mandible implantation, and has observed this patient for two and half years after operation. The author satisfy that this patient has been recovered.