A vehicular air conditioning system of the present invention comprises an air conditioning unit which forms an air flow, a first vent 8 through which the air flow formed by the air conditioning unit is blown out toward a passenger, a second vent through which the air flow formed by the air conditioning unit is blown out in an upper direction of the vehicle, an air flow blowout switching unit which switches between blowout from the first vent, and blowout from the second vent at predetermined intervals. The air flow blowout switching unit includes a door unit which closes one of the first and the second vents and opens the other vent, and a control unit which controls the closed state and the opened state of the door unit.