With the recent development of tumor prosthesis, limb salvage technique has attributed to the preservation of the limb function in patients with malignant bone tumors around the knee without substantial difference of local recurrence and the survival rate. From Feb., 1991 to Sep., 1992, 9 patients were treated with limb salvage operation with total knee arthroplasty due to the malignant bone tumor around the knee at Dept. of Orthopedic Surgery, Kyungpook National University Hospital. We applied the above procedure mainly to young adult whose tumor was expected to be excised wide marginally without damaging major neurovascular structures. We evaluated the functional status of all 9 patients(4 osteosarcoma, 2 chodrosarcoma, 2 malignant fibrohistiocytoma, 1 malignant giant cell tumor) to estimate the efficacy of limb salvage operation with tumor prosthesis total knee arthroplasty. Mean follow up period was 10 months. Primary tumor site was 4 in distal femur, 5 in proximal tibia and stage was 4 IIa, 5 IIb. Range of the motion of knee is maximum 0° -110° minimum 0°-45° in distal femur and maximum 0°-90° minimum 10°-50° in proximal tibia. Functional status estimated according to Enneking method was Excellent in 1 case, Good in 2, Fair in 1 in distal femur, and Excellent in 3, Good in 1 Fair in 1 in proximal tibia. In summary, we carefully concluded that wide marginal resection and total knee arthroplasty was valuable procedure in malignant bone tumor around the knee in functional aspect and the functional result of the proximal tibia group was slightly better than that of the distal femur group.