Abstract: In this paper,the heat transfer ability of the heat source tower and the heating capacity of combining the heat source tower and the heat pump host is separately tested,and a comparison of heating capacity with the air-cooled heat pump is conducted.The results show that under the condition of constant temperature difference between the inlet air and solution,the heat absorbed by the tower from the air increases with the decrease of the ambient temperature.The volatilization of solute in solution plays an important role in heat absorption of heat source tower.Under the condition of variable temperature difference between the inlet air and solution,the temperature difference between the ambient temperature and the evaporation temperature decreases with the decrease of the ambient temperature,at the same time the heat absorbed by the heat source tower decreases too.Although the air contains less moisture under low temperature conditions,the heat pump system with heat source tower has greater advantages on latent heat exchange compared to other heat pump systems using air as heat source.