An air conditioning system for a vehicle includes a heat pump type cooling device (A) having a first circulation route (1), and also includes a circulation device (B) for heating having a second circulation route (8). A water-cooled condenser (3) in the first circulation route (1) is placed in the second circulation route (8) and releases heat of a first refrigerant to a second refrigerant. A flow path change valve (14) for changing between the radiator (10) side and a radiator bypass flow path (13) is provided in the second circulation route (8). In heating operation, the second refrigerant is caused to flow to the radiator bypass flow path (13) by the flow path change valve (14) and air heated by a heater core (12) is introduced as air conditioned air into a vehicle interior. In cooling operation, the second refrigerant is caused to flow to the radiator by the flow path change valve (14) and air cooled by an evaporator (6) is introduced as air conditioned air into the vehicle interior.
