From 1981 to 1991, twenty one vascularized bone grafts had been performed for the treatment of large bone defects of the extremities, with average follow-up of 65.4 months. Fibulae were used in 15 patients Including two cases of osteocutaneous flap, iliums in 5 including two of osteocutaneous flap, and osteocutneous rib in one. Ten of these patients were treated for segmental defects derived from trauma or infection sequelae of long bones, while eight for locally aggressive benign or malignant bone tumors ; and three for congenital pseudarthrosis of tibia. The location of the lesions were 8 cases in tibia; 7 in humerus ; 3 in forearm bone ; 2 in foot ; and 1 in femur. The length of bone defects were averaged as 10 cm, ranging from 3 to 17.5. In eighteen patients(85.7%), the operation was successful. The duration from operation to bony union was average 5.1 months on successful cases, and three of them needed additional procedures, such as bone graft and electrical stimulation to promote bony union. Local recurrence was found in one case of chondrosarcoma, resulting in AK amputation. Wound infections were noted each one case on donor or recipient site. In five cases, the fracture of grafted bone, which united with cast immobilization in four, occurred average 16.7 months after operation.