To introduce the use of single arm external fixation assisted reduction and closed complex intramedullary nail fixation for the treatment of femoral shaft fracture operation method and to study its effects.From June 2008 to October 2012, 24 patients with femoral shaft fractures were treated with unilateral external fixation assisted by closed reduction, interlocking intramedullary nail fixation. Among the patients, 19 patients were male and 5 patients were female, ranging in aged from 20 to 68 years,with an average of 45.6 years old. The fracture was caused by traffic accidents in 14 cases, by falling in 6 cases, by heavy bruising in 4 cases. Admission diagnosis was femoral shaft fracture. Operation was performed after traction from tibial tubercle for about 1 week.All the patients were followed up, and the duration ranged from 6 to 24 months, with a mean of 16.2 months. The X-ray showed fracture healing time ranging from 11 to 17 weeks, with an average of 13.8 weeks. All fractures healed without nails broken or close joint dysfunction. According to femoral shaft efficacy evaluation standards, 23 patients got an excellent result, 1 good.Unilateral fixator assisted closed reduction and interlocking intramedullary nail fixation for the treatment of femoral shaft fracture has following advantages: less trauma, simple operation, effective reduction, high rate of fracture healing, and low complication rate.