Objective To evaluate the effectiveness of correction of posttraumatic flexion contracture of knee (FCK) using Ilizarov technique.Methods Six male patients with posttraumatic FCK,aging from 9 to 43 years (mean,24.5 years),treated by using Ilizarov technique from January 2006 to December 2010,were retrospectively analyzed.The preoperative flexion deformity of knee ranged from 35° to 85° (mean,47.6°),and the range of motion ranged from 0° to 70° (mean,15.8°).Among them,five patients had old fracture of knee joint combined with equinus foot deformity (deformity ranging from 25° to 37°,with an average of 31.8°); one patient had femoral supracondylar fracture.We used circular external fixator to correct the FCK and equinus foot deformity gradually,the knee arthrodesis operation was performed in 4 patients because of the damaged hone structure and poor soft tissue condition.Results All patients were followed up for 12-22 months (mean,18 months).The flexion of knee joint was recoverd from preoperative 47.67°±18.63° to postoperative 9.33°±3.50°.Plantar flexion of ankle joint in five equinus foot deformity was recovered from preoperative 31.80°±4.65° to postoperative 3.00°±4.47°.The kuee joint was arthrodesised successfully in 4 patients and the other 2 patients got 30° and 75° ROM.All the patients can walk with a cane,and satisfied with the result of treatment.Pin-site infection was found in 4 patients and was controlled within two weeks.Conclusion Ilizarov technique is an effective treatment method for posttraumatic FCK.Knee arthrodesis should be performed when patients had damaged bone structure and poor soft tissue condition.