Under the effective chemotherapy protocol, physeal distraction could be used as an effective limb salvage in the growing children with lower-limb malignant metaphyseal bone tumours and could actively prevent leg length discrepancy or malalignment that profoundly affects function. In this paper, we report a 7-year-old boy with right distal tibial osteosarcoma but not yet invaded the epiphysis, which underwent surgical treatment after effective chemotherapy. The surgical procedure included two phases: epiphysiolysis (physeal distraction) and en-bloc resection of tumor and distraction osteogenesis. In the first phase, after osteotomy of the proximal fibula was performed, two Ilizarov rings were attached to the proximal tibia and one Ilizarov ring was applied to the distal tibia. At same time, U-shape ring as an important external fixator was been used in the axis of rotation of the ankle joint in order to balance the stress from the surrounding tissues, increase distracting stabilization and prevent the deformity or contracture of ankle joint. In the second phase, the tumor bone (5.7 cm) was en bloc resected by diaphyseal osteotomy. Distraction osteogenesis was commenced 1 week postoperatively at a rate of 1 mm twice a day. The patient was reviewed by X-ray intermittently. The new bone was formed and the entire bone defect was covered in four months after the operation. Doxorubicin and cisplatin as the neoadjuvant chemotherapy protocol are effective to osteosarcoma and chemotherapy process did not adversely affect the union. Through this technique, the right distal tibial epiphysis was reserved successfully. At the last follow-up, there are no local recurrence or metastasis and we achieve to prevent leg length discrepancy or malalignment that profoundly affects function.