Supracondylar osteotomy of humerus for traumatic cubitus varus deformity is usually considered to be difficult due to incidences of complications such as recurrence and nerve palsy. The most difficult is maintaining the correction after operation, 9 cases who were under 7 years of age had a modification of French's osteotomy and 29 cases who were above 7 years of age had a modification of Langenskiold osteotomy. A plaster splint was postoperatively applied with the elbow extended and flexed alternatively. We achieved excellent and good result in 34 out of 38 cases. This technique of ours is recommended.