The Stars Water to Water Heat Pump air conditioning system is healthy, environment agreeing, energy conservative system of internationlly advanced standard, which is the achievement of cooperation of Guangzhou (Stars) Refrigerating Equipment Co.,Ltd. and the Poly Research and Design Institute of Zhengzhou Industrial University, the grade institute. The air conditioning system transforms the underground low level energy, which can't be used directly, to high-level usable energy, taking the advantage of constant temperature (5-20 centigrade), taking underground water as the main energy source, electricity acting as an auxiliary source. In winter the system absorbs heat from underground water; in summer it discharge heat to the underground water, working in this way to satisfy the requirement o f heat in winter and cooling in summer, and supply hot water for living usage utilizing part of the heat. This new air conditioning system saves 50% power compared with the common air conditioning system, so it is high efficient, healthy, no-pollution, heating and cooling air conditioning system utilizing regenerative energy, suitable to be used in commercial building, common building, residence, school, hospital etc., especially suitable to be used in the regions where environmental temperature alters much in different seasons in a year.