Objective: The aim of this study was to determine stand protocol for patients with extremity osteosarcoma by case following up after neoadjuvant chemotherapy and limb salvage operation. Methods: Between January 2000 and January 2007, 121 patients with extremity osteosarcoma were eligible for this analysis. After being graded according to Ennek- ing classification, all patients were preoperative chemotherapy (methotrexate, cisplatin, doxorubicin, and ifosfamide. Some patients with IIB tumors received extra interventional embolism). And postoperatively, the same protocols were employed, but poor responders (tumor necrosis < 95%) received more treatment cycles than good responders and took some new medicine in place of the former one. Most of patients underwent limb salvage operation (99/121), and the Musculoskeletal Tumor Society Score (MSTS) was used to evaluate the recovery of their limb functions. Results: The followed up last for average 37.3 months (range: 16–101 months). Most patients (76/121) survived, and the overall survival (OS) was 62.8%. Forty-seven of the 121 patients underwent osteoarticular allografts, among which 12 cases of disunion between the host bone and graft bone, 4 cases of allograft absorption and 3 local recurrences appeared. The mean MSTS score was 22.6 ± 4.13, with an excellent limb function in 17 patients, good in 19 patients, fair in 6 patients and poor in 7 patients. The overall excellent and good function outcome was obtained in 76.6% of the patients. Fifty-two of 121 patients underwent custom-made or modular tumor endoprosthesis replacememt, among which 1 case of aseptic loosening, 1 case of peri-prosthesis infection and 4 local recurrences appeared. The mean MSTS was 24.32 ± 3.85, with an excellent limb function in 28 patients, good in 16 patients, fair in 5 patients and poor in 3 patients. The overall excellent and good function outcome was obtained in 84.6% of the patients. Conclusion: Neoadjuvant chemotherapy and limb salvage surgery are effective methods to treat osteosarcoma at present, although some patients still dying from postoperative metastases. Therefore, early diagnosis individualized treatment and exploring for new and effective therapeutic strategy should be the key to an ideal treatment for osteosarcoma. Objective: The aim of this study was to determine stand protocol for patients with extremity osteosarcoma by case following up after neoadjuvant chemotherapy and limb salvage operation. Methods: Between January 2000 and January 2007, 121 patients with extremity osteosarcoma were eligible for this analysis. After All patients were preoperative chemotherapy (methotrexate, cisplatin, doxorubicin, and ifosfamide. Some patients with IIB tumors received extra interventional embolism.) And postoperatively, the same protocols were employed, but poor responders (tumor necrosis <95%) received more treatment cycles than good responders and took some new medicine in place of the former one. Most of patients underwent limb salvage operation (99/121), and the Musculoskeletal Tumor Society Score (MSTS) was used to evaluate the Results of The followed up for average 37.3 months (range: 16-101 months). Most pat Among the 12 cases of disunion between the host bone and graft bone, 4 cases of allograft absorption and 3 local recurrences. The mean MSTS score was 22.6 ± 4.13 with an excellent limb function in 17 patients, good in 19 patients, fair in 6 patients and poor in 7 patients. The overall excellent and good function outcome was obtained in 76.6% of the patients. Fifty-two of 121 patients underwent custom-made or modular tumor endoprosthesis replacememt, among which 1 case of aseptic loosening, 1 case of peri-prosthesis infection and 4 local recurrences. The mean MSTS was 24.32 ± 3.85, with an excellent limb function in 28 patients, good in 16 patients, fair in 5 patients and poor in 3 patients. The overall excellent and good function outcome was obtained in 84.6% of the patients. Conclusion: Neoadjuvant chemotherapy and limb salvage s urgery are effective methods to treat osteosarcoma at present, although some patients still dying from postoperative metastases.