An auxiliary handbrake operating device is positioned between the handbrake assembly mounted on the bicycle frame and the normal handbrake operating device along the brake wire. The brake wire goes directly through a wire hole on the auxiliary handbrake operating device so that the normal handbrake operating device at the end of the handle bar could pull the brake wire and, therefore, the brake arms of the handbrake assembly to brake the bicycle without any interference as usual. On the other hand, when the auxiliary handbrake operating device is gripped, it will push a cable wrap around the brake wire which in turn would force the handbrake assembly to brake the bicycle.