Abstract: Based on the first and second laws of thermodynamics,a mathematical model of energy and exergy analysis of the solar graded solution heat collection/regeneration system with heat recovery is established. Exergy efficiency and regeneration efficiency of this system are compared to reveal the influence of various factors on the thermodynamic performance of the system. It is found that exergy efficiency of the system is higher than regeneration efficiency,indicating that the utilization degree of energy quality is higher than that of energy quantity. The optimal ranges of these parameters are obtained by analyzing the exergy loss coefficients of all components of the system. The regeneration efficiency and exergy efficiency of the optimized system are 26.6% and 32.3%,respectively.The analysis on exergy loss rate of the system shows that the weak links in the system are the first-grade solar collector/regenerator,the second-grade solar collector/regenerator and the packed dehumidifier.