The water source heat pump is the low-grade heat energy which in the use ground water, the surface water or other water source water save, according to the Garnot cycle principle, with the aid of the compressor system, through the few high grade electrical energy's input, takes massively unceasingly the water source water in drainless, but not the easy use's low-grade heat energy to replace, causes it to turn may the use high grade heat energy, realizes the low potential energy to the high potential energy shift one kind of renewable energy source the cold heat source which forms from this using the technology, not only may satisfy each kind of building winter heating, summer for the cold demand, but may also simultaneously solve the life hot water supply problem, is one kind of energy conservation environmental protection and the advanced practical new air conditioning technology, already became heating to supply in the cold system to be more highly effective, the more economical first choice plan.