Caldwell342.7 introduced the hanging cast technique in 1933, and it has become one of the most widely accepted and successful methods for treatment of humerus shaft fracture. The cast is applied to displaced fractures of the humeral shaft with shortening, and also to oblique and spiral fractures. However, fractures of the humerus in children undel the age of tweive should not be treated with the hanging-cast method. It is practically impossible to keep the arm in the dependent position while the child is asleep. Especially for the obese obese person, open reduction and internal flxation may be the child is asleep. Espeially for the obese person, open reduction and internal flxation may be required to prevent distraction and non-union. We experienced five patients which fractured humeral shaft with hanging-arm cast with strong light plastic cast, and so the results were excellent without distraction and angulation after early joint motion with functional brace application.