Objective:To explore open reduction through medial exposure for Gartland Ⅲ supracondylar fractures of the humerus in children. Methods:216 cases with Gartland Ⅲ supracondylar fractures of the humerus received open reduction through media exposure plus crossed Kirschner wire internal fixation. Results:All cases were followed up for 1 month to two years and four months. According to Flynn criteria, the excellent and good rate was 92.13%. Conclusions:Open reduction through media exposure plus crossed Kirschner wire internal fixation is a safe and effective treatment for Gartland Ⅲ supracondylar fractures of the humerus in children. Incision scar is at the medial elbow and concealed. Correction of ulnar deviation, ulnar tilt and internal rotation can be effective in reducing the incidence of cubitus varus.