The cases of 160 patients who had a displaced supracondylar fracture of the humerus were reviewed retrospectively. According to the Flynn's criteria, the results of treatment were excellent 33%, good 53%, fair 10%, poor 4%. No neurovascular complication was appeared. In two cases, cubitus varus deformity was appeared to be related with incorrect reduction. We believe that percutaneous k-wire fixation is excellent method in treatment of the displaced supracondylar fractures in children. There was no significant difference of clinical results among methods of percutaneous K-wire fixation but lateral 2 and medial 1 cross pinning has advantages : easy technique in insertion of lateral 2 pins, biomechanical stability and removal of medial pin in the irritation of ulna nerve without significant influence of stability.