The supracondylar fracture of the humerus is the most common fracture of the elbow in children and is occasionally associated with significant residual complications such as cubitus varus deformity. Clincal analysis was performed on 32 patients with displaced supracondylar fractures of humerus, who were treated either by closed reduction and percutaneous pinning or by open reduction and internal fixation. The results were as follows : 1. The average age of the children was 6.8 years old in both sexes, and male to female was 21 : 11. 2. The extension type was 26 cases(82%), flexion type was 6 cases(18%) and the left side was more frequently involved. 3. According to Pirone classification, type II was 14 cases, type III 18 cases. 4. There was no significant difference in the mean duration of bony union between the percutaneous group and the open reduction group. 5. Cubitus varus deformity and limitation of elbow motion were more common complications in open reduction group.