Objective This article provides a reform operative method for repairing non union in proximal or middle ulna Methods According to anatomical stady of recurrent interosseous artery from both blood supply and biology strength designs the transposition of proximal ulna periosteal bone flap, combining external fixator to repair non union in ulna Results Twelve cases of non union in proximal or middle ulna were treated by this means, these results were encouraging Conclusions Periosteal bone flap based on recurrent interosseous artery has a stable position, reliable blood supply and no injuring main vessel Moreover external fixator has many advanture, such as steady fixation, rarely damage, simply operation, function train early to prevent producing stiff joint, activate fracture with physiological force, Both can prompt the healing of fracture, It is an efficient method to cure non union in proximal or middle ulna