From June 1993 to May 1997, 12 patients aged from 13 to 41 years were treated for infected nonunion with bone defect by the Ilizarov technique. Of 12 cases, 9 cases were tibia and 3 cases were femur. The cuases of nonunion were open comminuted fractures with initial bone loss and bone defect after removal of sequestrum. Infection was managed by radical resection of the infected necrotic bone and insertion of antibiotics mixed cement beads. Bony defects were gradually closed by the Ilizarov's internal bone transport technique, and final equalization of leg length inequality was achieved by means of external lenghthening technique. Corticotomies were performed at the proximal level(7), at the distal level(5). The average optained length averaged 4.8cm in length and healing index averaged 67.4days/cm According to paley and Catagni's callification bony and functional results were either excellent or good execpt I case (nonunion, poor bony result). The complications (devided by paley to 3 categories: problems, obstacles, complications) were pin tract infecton(8), pain(5), mild flexion contracture of joint(1), delayed consolidation(3), soft tissue impingement(2), joint stiffness(3) and nonunion(1). We concluded that Ilizarov techinque was very effective for treatment of infected nonunion with bone defect and soft tissue defect.