Bone defect of the long bone continues to challenge orthopedic surgeons. It is usually very difficult to obtain union. Ilizarov ext. fixation has recently gained popularity as a multifactorial approach to the management of tibial bone defect because nonunion, bone defects, limb shortening, and deformity can all be addressed simultaneously with the Ilizarov apparatus. From February 1992 to May 1993 at the department of orthopedic surgery, Inje University Pusan Paik Hospital, 9 patients aged from 8 to 37 years were treated for tibial bone defect. The causes were open comminuted fractures with initial bone loss and bone defect after removal of infected necrotic bone. Bony defect size was ranged from 2cm to 14cm, averaging 7.2cm. Bony defects were gradually closed by the Ilizarov's internal bone transport technique, and final equalization of leg length discrepancy was achieved by means of external lengthening technique. Soft tissue defects were treated with secondary closure, split thickness skin graft, and muscle flap. The average healing index was 42.8 days/cm. According to Paley's classification the complications were developed as follows; The problem included pin tract infection(9), knee flexion contracture(4), and intractable pain(1), the obstacles included delayed union(3) and premature consolidation(1), the complication included nonunion(9) and equinus ankle(1). At an average 1 years follow up, according to Paley and Catagnl's classification, body and functional results were either excellent or good in 7 cases. So, we recommend that Ilizarov technique is very useful treatment for open fracture with bone loss, bone defect after removal of infected necrotic bone and limb shortening.