Abstract: A steel structure including pre-stressing brackets for improving load-carrying capacity and serviceability comprises: a steel girder; a plurality of connecting brackets connected to the bottom surface of the steel girder spaced and apart from one; and a cover plate connected to the bottom surfaces of the connecting brackets. Since the cover plate is installed regardless of the connecting portion of the steel girder, pre-stressing section can be consecutively formed therefore pre-stress effect is improved. Moreover, since the connecting brackets space the cover plate a constant distance from the steel girder, the moment of inertia is increased so the span of a bridge might be increased.