Abstract: A gait trajectory guiding device of a gait rehabilitation apparatus is disclosed. The gait trajectory guiding device includes a pair of guideway actuating plates (11), which are arranged parallel to each other, and each of which is provided with a horizontal screw, and a pair of guideways (20), which are provided on each guideway actuating plate. Each guideway is individually moved by rotation of the corresponding horizontal screw in the longitudinal direction of the guideway actuating plate. The device further includes footboards (30), which are coupled to the corresponding guideways such that the front and rear parts of each footboard are individually adjustable in height. Therefore, the footboards are actuated by the guideways along trajectories similar to the movement of the feet of a person when actually walking, thus enabling a user to conduct gait training in a correct walking motion, thereby increasing rehabilitation effect.