Objective To study the clinical feasibility of the prosthetic composites of the intercalary allograft and the segmental allograft in reconstruction of the skeletal defect after the limb tumor resection. Methods Between August 1999 and December 2003, 28 patients with skeletal defects after the limb tumor resection were treated with the intercalary allograft or the segmental allograft megaprosthesis composite for reconstruction of skeletal defects. The bone involvements were observed in 16 patients with osteosarcoma, 4 patients with parosteal osteosarcoma, 5 patients with Ewing sarcoma, and 3 patients with soft tissuesarcoma. Preoperative biopsy was performed on all the patients, and the pathological result was confirmed after surgery. According to the Enneking system, 5 patients were grouped in ⅠB and 23 patients in ⅡB. The patients with osteosarcomaor Ewing sarcoma received the standard chemotherapy before and after operation.Eighteen and ten patients received the segmental allograft prosthetic compositereplacement and the intercalary allograft with the interlocking intramedullary nail fixation, respectively. The functional outcome was evaluated by the MSTS score. Results According to the follow-up for 5-48 months (average, 24 months), local recurrence was observed in 1 patient who underwent amputation eventually. Of the 28 patients, 3 developed nonunion of the allografthost junction accompanied by severe resorption and 2 developed deep infection. No allograft fracture was seen in the patients. Most of the patients achieved a good functional result with an average MSTS score of 23.4. ConclusionThe prosthetic composite replacement of the intercalary allograft and the segamental allograft can be used n the skeletal defect reconstruction after the limb tumor resection. The stablecontact in the allografthost junction and the b intramedullary internal fixation can help to reduce the complication rate of the allograft.