Subtrochsnteric varization osteotomy with open wedge technic was performed for the Legg-Calve-Perthes disease patients of 6 years to 9 years of age. Open wedge technic is less complicated with unwilling effect of postoperative leg shortening than closed wedge technic, but has seldom performed for the patients over 5 years of age because of possible delayed or nonunion of osteotomy site. Authors trial of this technic in a older patient(6 to 9 years of age) showed excellent post-operative result with noneventual post-operative course including delayed or nonunion.