Clavicle fracture is one of the most common fractures and can be treated by conservative methods with a high rete of union and operative treatment itself was rearded as a cause of nonunion. But recently, we experienced some cases of delayed or nonunion following conservative treatment especially in high energy trauma patient. So we tried to treat 35 cases of clavicle fractures by open reduction and internal fixation with or without bone graft and analyzed the results. Results were as following. 1. The functional results were excellent in 16 cases(45.7%), good in 13 cases(37.1%), fair in 4 cases(11.4%) and poor in 1 case(0.28%), except 1 case of initial brachial plexus injury. 2. Of the 34 cases (except 1 case of nonunion), average time to union was 8.2 weeks in Knowles pin fixation and 8.4 weeks using plate with or without bone graft. Knowles pin fixation and 8.4 weeks using plate with or without bone graft. In the treatment of flesh clavicle fracture for early rehabilitation especially in young patients, open reduction and internal fixation is thought to be good method.