Taking the integrated gaseous contaminants and moisture adsorption potential of desiccant material, a new heat pump assisted solid desiccant cooling system (HP-SDC) was proposed based on the combination of desiccant rotor with heat pump. The HP-SDC was designed for dehumidification, cooling and air purification aimed at improving indoor air quality and reducing building energy consumption. The heat and moisture transfer in adsorption desiccant rotor was theoretical modelled with one-dimensional partial differential equations. The theoretical model was validated with experimental measurements, and the results showed the model could be used to predict the heat and moisture transfer in desiccant rotor. The air thermal conditioning process and energy consumption of HP-SDC was then experimental measured under varied outdoor thermal environments. Results showed that compared to conventional ventilation system, the energy performance of HP-SDC was more efficient mainly due to high efficient air purification capacity, reduction of cooling load and raised evaporation temperature. The energy performance of HP-SDC was sensitive to outdoor humidity ratio. Further improvements of HP-SDC energy efficiency are suggested to be focused on low regeneration temperature desiccant rotor and more efficient high temperature refrigerant. (C) 2017 Elsevier B.V. All rights reserved.