When the non-union gap in a long bone is more than half of the diameter of the bone at that level, it presents a significant challenge to traditional bone grafting technique. Even if there are several good ways for this problem, such as shortening, traditional various bone grafting, electrical stimulation and free vascularized bone graft, most of these techniques have some difficulties to maintain the stability of fracture post-operatively, and we have to keep their extremities into a cast or external fixator so long. So we have attempted to treat the large osseus gap non-union in long bone with fixation of heavy duty or condylar plate on one side of fracture for fracture stability, a long tibial corticocancellous strut graft on the other side of fracture for fracture stability and rapid bony union, and extensive cancellous chip bone graft between the plate and tibial graft to enhance the bony union. We have experienced 9 cases of large osseus gap non-union in long bone with this technique from March 1981 to September 1986 at the department of orthopaedic surgery, St. Mary's hospital, Catholic University Medical College. 1. Their, 7 males and 2 females, average age was 38 years old, with a range of 24 to 53 years old. The distribution of the involved bone was 6 femur, 2 humerus, 1 radius and ulna with 1.4 years of average duration of non-union, ranged from 7 months to 2.4 years. The average gap from normal bone to normal bone was 4.8cm, with a range of 2.7cm to 7.4cm. The average number of previous surgical procedures was 4, with a range of 2 to 7. Four of the nine patients had quiescent osteomyelitis. 2. Post-operative immobilization with splint or cast was applied for 6 weeks for upper extremity and 8 weeks for lower extremity followed by active R.O.M. exercise and non-weight bearing crutch walking. 3. Five of the nine cases(55.6%) had completely bony union. This occured on an average 8 months post-operatively and was faster in the forearm bones and femur than in the humerus. An additional cancellous bone graft was done in two. But other two of the patients had subsequent amputation because of recurrent and uneontrollable osteomyelitis stirred up by the surgery. 4. This procedures was proved to be one of valuable adjuvant method in treatmqnt of large osseous gap non-union of long bones.