The greenhouse was designed and constructed by using multi-layer covering and reducing heating space measure. The temperature and relative humidity of air in the greenhouse were determined in night when heated by water source heat pump. The result showed that horizontal distribution of temperature was uniform in the east-west direction of the compartment，there was 0.9℃gradient in 12.0-m distance in the south-north direction 1.5-m above the ground and there was 1℃ vertical gradient 2.0-m above the ground, relative humidity of air in the greenhouse was lower than 80% during 24:00—08:00. The actual coefficient of performance of the experimental water source heat pump was 3.31.The experimental greenhouse heated by water source heat pump saved energy by 46.5%, compared with that in the greenhouse heated by boiler using coal fuel. However, the heating cost was 82.2% higher in the former greenhouse than in the later. Based upon adjustment, the greenhouse heated by water source heat pump could saved energy by 69.1% and the corresponding heating cost was only 5.8% higher, compared with these in the greenhouse heated by boiler using coal fuel.