The invention provides a constrained structure of vehicle slide-door, capable of making the slide-door slide on the fore and aft direction of the vehicle to open and close the vehicle door opening at the side surface of the vehicle-body, wherein a latch lock is set on the vehicle-body side vertical wall surface facing the vehicle door opening and the latch lock is of U shape, observed from one side of the vehicle-body side surface; an insertion hole is set on the side vertical wall surface of the slide-door and the latch lock is inserted into the insertion hole when the slide door is closed; and a pair of notch parts capable of being jogged with the latch lock at a cabinet side of the insertion hole, when the load is applied on the slide-door from the cabinet side towards the outside of the cabinet, the latch lock is partly jogged with the notch parts by the insertion hole. Thus, even though it is difficult to ensure the space, when the load is applied on the slide-door towards the outside of the cabinet, the slide-door is constrained to effectively constrain the movement of the slide-door without prejudice to normal opening and closing operation of the slide-door.