Disclosed is an orthodontic archwire with a varied cross-sectional structure. The archwire includes a rectangular cross section along every region, and a height and/or a width of the cross section between at least one ligating portion configured to be ligated to a slot of a bracket and the bracket is different from each other. The archwire includes an anterior region located at a center thereof, and a pair of posterior regions located at left and right sides of the anterior region. The anterior region includes at least one anterior wire protrusion protruding in a direction toward a patients tongue from the ligating portion to be ligated to the slot of the bracket, and the posterior region has a constant cross section or has posterior wire protrusion protruding in the direction toward the patients tongue from the ligating portion.
