Objective：To evaluate the results of single-frame external fixator in treating obsolete Monteggia’s fractures in children．Methods：From January 2008 to December 2011，a total of 22 children with obsolete Monteggia’s fracture were reviewed including 14 males and 7 females with an average age of 7.4-year-old（ranged from 2-year-old to 14-year-old）. According to the Boda classification system：there were 12 cases of type Ⅰ（extension type，54.5%），4 cases of type Ⅱ（flexion type，18.3%），5 cases of type Ⅲ（adduction type，22.7%），1 case of type Ⅵ（4.5%）. All patients were operated with single-frame external fixator after the reduction. The plaster was kept for 4-6 weeks postoperatively. Results：All patients were available at the final follow up with a mean of 2.8 years（ranged from 2 years to 4.8years）. Good union was achieved in all cases after 11.6 weeks（ranged from 10 weeks to 20 weeks）. The radio－humeral joints of 21 cases were returned to normal and subluxating of the radius was observed in one case. There was no ulna nonunion and malunion after the operation. According to the Mackay scoring system，the motion function of 18 cases（81.8%）was excellent，3 cases（13.6%） was good，1 case（4.6%） was poor，with the excellent and good rate of 95.5%. No case of atrogenic vascular injury，os－seous connection of ulna and radius，capitellum and radial head fracture was observed. Conclusion：Single-frame external fixation is effective in the treatment of obsolete Monteggia’s fractures in children. It can rectify the elbow malformation，adjust the operation and restore elbow function. Single-frame external fixation is simple，safe，minimally invasive and has good theraputic effects.