Supracondylar fracture of the humerus is the most common fracture of the elbow in children For period of 4 years from Jan. 1980 to Dec. 1983, 54 children with dispaced supracondylar fracture of the humerus were classified by direction of displacement of distal fragment and treated by immediate closed reduction after lateral skeletal traction. 32 cases of these were followed up for more than 6 months. The results were obtained as follows.: 1) The most common incidence (79.6%) was 5 to 12 years of age and male and female ratio was 2.4 : l. The left humerus was involved in 35 cases (64.8%). 2) Of all fracture, extension type was 96.3% and flexion type 3.7%. 3) Under the exact anteroposteier and lateral views, fractures were classified by displaced direction of distal fragment. Immediate closed reduction was done by using thick and strong periosteal hinge after lateral skeletal traction. The more accurate anatomical reduction was obtained by maintenance of reduction state and further correction during lateral skeletal traction, and complications such as VIC, loss of reduction were lessened probably. 4) For follow up study of 32 cases, final result were analized according to Mitchells classification. Excellent results were obtained 23 cases (71.9%) Good results were 8 cases (25.0%) Unsatisfactory result was 1 case (3.1 %) 5) In 2 cases of treatment failure, the brachialis muscle was buttonholed by metaphyseal spike of the proximal fragment. 6) During lateral skeletal traction, superficial infection was developed through pin tract in 4 cases. These were treated by the administration of antibiotics and there were no complication such as osteomyelitis.