Fracture of the tibial shaft is the most common fracture of the long bones. And due to its frequency, mode of injury, fracture patterns, and numerous complications, the methods of its treatment is versatile. Recently flexible Ender nailing under the image intensifier has been widely used as a simple procedure. We analyzed 31 cases of tibial shaft fractures which were treated by a closed intramedullary Ender nailing from Jan. 1989 to Jun. 1991. The result obtained were as follows: 1. Tibial shaft fractures were more common in male (20 cases, 65%) and peak incidence of age was 20-30 years (15 cases, 48%). The main cause of injuries was traffic accident (15 cases, 48%). 2. The most common fracture site was middle one-third (22 cases, 71%), and five cases (16%) among 31 were open fractures, 26 cases (84%) were closed. Seventeen cases (55%) were comminuted. 3. The mean time of clinical union was 13.3 weeks and that of radiological bony union was 16.2 weeks. The mean radiological union time was 15.2 weeks in the proximal one-third fracture of tibia, 16.1 weeks in the middle one-third fracture of tibia, 17.2 weeks in the distal one-third fracture of tibia. Also that was 17.2 weeks in the open fractures, 15.2 weeks in the closed fractures. In conclusion, Ender nail is the simple internal fixation device which allows early weight bearing which decreases the complication.But the concepts of diverging the distal part of the nail is important to maintain anatomical reduction and get rotational stability. Also this method can be used in treating open fracture,segmental fracture, and unstable fracture which stable fixation can not obtained by other procedures.