A gait training device operates in cooperation with a wearable motion assist device that specifies a walking phase of a wearer, and applies power to the wearer in correspondence to the walking phase of the wearer, the gait training device including: a body weight support device that lifts up the wearer to support a weight applied on feet; a moving unit that is movable according to a walking motion of the wearer; and a control device that controls a moving speed of the moving unit and/or an amount of body-weight support by the body weight support device based upon a position of a center of gravity of the wearer detected by the wearable motion assist device.