1. The author found that the characteristic radiologic finding of the flexion-valgus type of supracondylar fracture of humerus in children is Y shape bifurcation of the distal end of proximal fragment on lateral view. 2. Thirteen cases were identified as the flexion-valgus type from among the 224 cases of supracondylar fracture. 3. Thirteen cases of flexion valgus type were classified into five types. 1) Dome shape fracture, along the upper border of the olecranon fossa-5 cases. 2) Transverse fracture, proximal to the olecranon fossa-2 cases. 3) Oblique fracture, through the posterior wall of supraconlylar-2 cases. 4) Oblique fracture, through the distal end of lateral column-3 cases. 5) Oblique frarture with partial injury of epiphyseal line of lateral condyle-1 case.