Abstract: Objective To investigate the clinical efficacy of closed reduction and percutaneous Kirschner wire fixation plus stage Ⅱ nerve exploration in the treatment of closed Gartland type Ⅲ humeral supracondylar fracture with radial nerve injury in children. Methods Closed reduction and percutaneous Kirschner wire fixation were performed in 42 children suffered from closed Gartland type Ⅲ humeral supracondylar fracture with radial nerve injury. Among them, 8 cases were underwent stage Ⅱ nerve exploration. All patients were followed up from 9 to 82 months(mean 50.3 months). The therapeutic effect was evaluated according to Flynn elbow joint function and radial nerve function assessment criteria. Results X-ray examination showed that 42 patients gained bone union without complications from 1 to 2 months after operation of fracture, and the Flynn elbow joint functional assessment criteria showed that there were 35 excellent cases, 5 good cases and 2 fair cases, with the excellent and good rate 95.23%. There were 27 excellent, 7 good and 8 poor according to the radial nerve function assessment criteria 2 to 3 months after operation of fracture, the excellent and good rate was 80.95%. Eight poor cases were underwent stage Ⅱ nerve exploration and the results were excellent after follow-up for 6 to 80 months. Conclusion It's simple and safe with small trauma and good recovery of elbow joint function to treat closed Gartland type Ⅲ humeral supracondylar fracture with radial nerve injury in children using the closed reduction and percutaneous Kirschner wire fixation. It is recommended to observe 3 months after fracture operation, the radial nerve function of most children recovered well. If the function of the radial nerve has not been restored, stage Ⅱ radial nerve exploration should be performed, and satisfactory results can be obtained.