1. The author found that the periosteal callus was formed on lateral side of the fracture in two cases of three posteromedially displaced supracondylar fracture of the humerus associated with fracture of distal end of ipsilateral forearm which were considered as the torsion fracture. 2. The above result was peculiar out come of the torsion fracture. 3. The characteristic radiologic findings of the torsion fracture are. 1) The fracture line of the proximal fragment is transverse and irregular(bursting). 2) Multiple longitudinal splitting and waving on entire fracture line of distal fragment. 4. Twenty eight cases of 236 cases of extension varus fracture supracondylar fracture of humerus were identified with torsion fracture. 5. The torsion fracture was combined with hyperextension fracture in 3 cases, extension-adduction fracture in 6 cases, shearing fracture by direct blow on anterior aspect of flexed elbow in 12 cases, and shearing fracture by backward thrust of forearm in 4 cases.