The supracondylar fracture of the humerus is the most common fracture of the elbow in children. New trends of treatment is that if satisfactory reduction is achieved by manual reduction, medial and lateral cross percutaneous pin fixation is better than others for stable fixation. Among many complications, cubitus varus deformity most commonly results from inaccurate reduction and failure in maintenance of fixation. The obliquity of the fracture, together with internal rotation, causes angular deformity. The angulation and coronal rotation, or tilting of distal fragment, often cause the deformity and limitation of motion of elbow. The porty-two Gartland type II, III supracondylar fractures of the humerus were treated by losed reduction or open reduction with percutaneous pinning or internal fixation from May 1993 to December 1995. The results were as follows; 1. the frequency of difference above 5degree in Baumann's angle was relatively high if fracture line is oblique on lateral roentgenogram or medial column comminution is present, that means unstable reduction. 2. In average, 2.7 pins were needed for reduction and maintenance of stability at this time. 3. Even though a few degree of rotation(5mm), translation(2-4mm) and angulation(5-10degree) were present at immediate reduction, carrying angle and Baumann's angle of follow-up period were often remained about the similar values compared with healthy side. If acceptable intraoperative carrying angle was achieved and a few degree of rotation, translation and angulation were permitted after reduction, varus deformity and limitation of motion of elbow were rerely caused. so repeating forceful manual reduction for anatomical reduction must be avoided because the final results may become progressively remodelled to normal.