In virtue of desiccant rotor's dehumidification and air-cleaning, a novel system combining desiccant rotor and heat pump combined system was proposed, in which the evaporator of heat pump cooled the hot air after desiccant rotor, while the condenser supplied regeneration energy to desiccant rotor. Therefore, an air source heat pump using R142b as refrigerant was developed and tested experimentally in psychometric room, which can simulate dehumidification air and regeneration air of the desiccant rotor. The cycle performance and discharge pressure of air source heat pump were investigated by varying the outdoor temperature and indoor air intake of the condenser. It showed that the heat pump could supply hot air at 79.2C, while outdoor temperature was (45 ± 0.2)°C and inlet air temperature was (27 ± 0.2)°C. In this case, the discharge pressure of compressor was within the range of compressor's normally operating pressure.The results suggested that hot air heated by the condenser could satisfy desiccant rotor's regeneration without other auxiliary heating systems.The cooling and heating capacity could be matched in this combining desiccant cooling system and the total energy consumed could be reduced significantly. Thus it could save energy and reduce environment pollution.