The authors have observed and treated the two patients with true bony ankylosis of temporomandibular joint in 16 years old school boy and 24 years old korean male. The ankylosed patients were treated by condylectomy and arthroplasty such as resin condylar head graft having been made into acrylic resin. 1. In 16 years old school boy, temporoandibular ankylosis of left side was surgical_y approached by condylectomy including coronoid process and posterior border of ramus and resin condylar head graft by means of interosseous wiring. 2. In 24 years old korean male, bilateral temporomandibular ankylosis was treted by bilateral condylectomies and resin condylar head grafts. 3. The mouth opening has been continued as 3-5cm since 13 months and 8 months before and facial appearances were very excellent.