Objective To investigate the effect of free transplantation of fibula composite tissue flap to the repair of forearm bone and soft tissue serious defect.Methods Eleven cases of reparing forearm bone and soft tissue serious defect through transplantation of free fibula composite tissue petal were applied from March 2004 to February 2011.The length of transplanted fibula composite tissue flap was 8-14 cm ; the flap area was 5 cm ×8 cm-20 cm ×20 cm.The curing situation on bone fracture was observed in 3,6 and 12 months after the surgical opration and the function of defected arm was evaluated in 1 year after surgical operation.Results All of 11 cases of fibula composite tissue flap were survived.The observation was undertaken for more than 12 months after the operation and the fracture section occured the characteristics of healing up in 3 months and fibula and arm bone occured well healed up in half a year; It scored 22.9 according to Enneking system after 1 year of the operation.The function of forearm rotation were classed as this:3 good cases,6 medium cases and 2 poor cases.In the 2 sural nerve bridging transplantation cases,one case was repaired of radial nerve inside static's two-point discrimination (s2PD) to 9 mm,another case was repaired of ulnar nerve distal volar little finger s2PD to 15 mm.All the cases could achieve making a fist with thumb and a thumb could be oppoiste to other 4 fingers,and the ankle joint movement was normal.Conclusion Transplantion of free fibula composite tissue flap to the repair of forearm bone and soft tissue serious defect is an ideal surgical operation method.