Liquid desiccant cooling system is a new type of air-conditioning system capable of saving energy. The dehumidification process dominates the performance of this system, while the thermal properties of the liquid desiccant play a key role in improving dehumidification effect. However, there is little work about how to choose a proper liquid desiccant that has a better performance. To settle this problem, a novel method is proposed to search an ideal liquid desiccant by applying the nonrandom two-liquid equation (NRTL equation). This idea is further applied to mixed LiCl and CaCl(2) solution to work out the right mixture ratio with a better dehumidification effect under certain working conditions. Moreover, the related experiments were carried out. The results show that: compared to single LiCl solution, the dehumidification effect could be raised by more than 20% with mixed LiCl and CaCl(2) solution. (C) 2008 Elsevier Ltd. All rights reserved.