Heat pump air conditioning system for vehicles

A heat pump air conditioning system having an outside heat exchanger (24) which is disposed in an engine compartment (31) of a vehicle is provided. The outside heat exchanger (24) consists of a first outside heat exchanger (12) disposed forward of an engine (11) and a second outside heat exchanger (13) disposed near the engine except the front, especially rearward of the engine. When heating the passenger compartment, the second outside heat exchanger acts as a heat absorber, utilizing the heat of the engine, and effectively heating the interior.