Most orthopedic surgeons were aimed at the rigid internal fixation on the surgical treatment of the fracture. And the compression plate was developed and regarded as an excellent rigid internal fixation device by its advantages of accurate anatomical reduction, early joint mobilization and shortening of the duration of the fracture healing, which are chief aim of A.S.I.F. method. During the period of January 1970 to December 1979, 67 cases of diaphyseal fractures of the long bones were treated with compression plate according to A.S.I.F. method at the Department of Orthopedic Surgery, College of Medicine, Seoul National University and results were obtained as follows: 1. The age of patient was ranged from 15 to 77, and the highest incidence was in the 3rd decade male group (31.4%). 2. Old fracture cases were slightly more than fresh cases, and the fresh femur fracture was the commonest. 3. The periods of the postop immobilization of fresh fractures were 3.7 weeks in humerun fracture, 6.3 weeks in forearm fractures, 8.7 weeks in femur fracture and 7.0 week in tibia fracture, and in old fractures about 4 weeks was longer than fresh fractures. 4. The bony union was accomplished in all cases between 8 week and 24 week. 5. The complication were 4 superficial infections, 4 deep infections, 1 delayed union and 9 joint stiffnesses. 6. Compression plate fixation is considered as an excellent method for the treatment of the fractures of the long bones.