The application of exergy analysis to the direct contact ice thermal storage system is investigated in order to assess the efficiencies of the system. The system consists of a compressor, a condenser, an expander and a direct contact evaporator. The exergy efficiency and its loss in each component have been evaluated by means of its exergy balance equation. The results show that the direct-contact ice storage system is more preferable than the general ice-on-coil system, and adopting an advanced compressor matched by the refrigerant is an efficient measure to improve the performance of the system.