The humerus is anatomically and phyelologically unique, such as, firstly, it is a non weight bearing bone, secondly, it has greatest range of motion, thirdly, when at rest while the person is standing, the axis of bone hangs vertically and is influenced by gravity, and conservative methods usually used in treatment. However, in the event of closed reduction failure, open fracture, multiple fracture, and old age, operative method may be employed. Authors reviewed and analzed 84 humeral shaft fractures which had been treated at the Department Orthopedic Surgery, Paik Hospital from Dec. 1979 to May 1988. The results were as follows : l. Among the 84 patients, male were 63 and female were 21. 2. The major causes of injury were a traffic accident. 3. The most frequent type and site of fracture was comminuted and middle one third. 4. The incident of radial nerve injury was 17 cases. 5. Of 84 cases, 22 cases were treated conservatively and 62 cases operatively. 6. The most common complication was non-union of 14 cases, of which 10 cases were treated with plate and bone graft and 4 cases with only bone graft.