It is well known that early diagnosis and early treatment is very important for the patient with congenital dislocation of the hip joint to have favorable function in the whole life. The goal of treatment is to replace the hip restored in containment with anatomical position. There have been various treatments in both conservative and surgical methods. In the past, conservative treatment has been prevalled, and since Salter has advocated innominate osteotomy, this surgical method could be successively replaced the treatment of congenital dislocation of the hip in the older age group. We have experienced 40 congenital dislocation of the hips out of 35 patients at the Department of Orthopaedic Surgery in National Medical Center. Clinical analysis has been performed, with average 3 years and 9 months follow-up study and the resuits are as follows. 1. Majority of the case was treated primarily at age between 12-24 months. 2. The preponderence of girl to boys was 33:2. 3. The affection ratio of left to right side was nearly equal as 16:14. Five out of 35 cases were involved at both sides. 4. The chief complaints were almost limping and limb shortening. 5. In 40 hips from 35 patients, 12 hips were treated by closed reduction, 3 hips by open reduction and 18 hips by Salters innominate osteotomy in the age group under 7 years old. By Seddon's classification, we obtained 11 excellent and good results out of 12 cases treated by closed reduction, 2 out of 3 hips by open reduction and 15 out of 18 hips by Saiters innominate osteotomy. 6. We performed femoral derotation osteotomy in 2 cases, 9 and 11-year-old patients. Steels operation with femoral shortening in 9-year-old girl and bilateral THR on 2 hips in 44-year-old patient. Result of derotation osteotomy belonged to clinical failure and THR belonged to excellent group by Seddons classification. 7. We experienced one case of avascular necrosis transiently, but finally healed delaying weight bearing.