A direction-limiting device for a stroller includes a mounting seat, a wheel assembly, and a direction-limiting device. The mounting seat includes a base coupled to a frame of a stroller. The wheel assembly includes a frame having a positioning hole. The direction-limiting mechanism includes a press button and a positioning member. When the press button is in an initial position, a lower end of the positioning member is disengaged from the positioning hole to allow free pivotal movement of the wheel assembly relative to the base. When the press button is pressed and then released, the lower end of the positioning member is engaged in the positioning hole, allowing joint movement of the wheel assembly and the base. Thus, even moving on a rugged road or hitting a bump on a road, the stroller will move straightly forward or rearward without the risk of turning over.