Proposed is a gas heat-pump system including: a compressor of an air conditioning module; a gas engine generating a drive force of the compressor; and a turbocharger primarily first-level pressure to a fuel-to-air mixture and supplying the fuel-to-air mixture to the gas engine or applying second-level pressure to the fuel-to-air mixture to which the first-level pressure is applied and supplying the fuel-to-air mixture to the gas engine.