In the present work, a multi-parameter optimization approach of Isopropanol-Acetone-Hydrogen (IAN) chemical heat pump is developed based on the entransy theory. In the optimization process, the total low-temperature heat consumed by the heat pump system generally decreases while the high-temperature heat recovered by the heat pump increases remarkably. When the temperatures of the reboiler and endothermic reaction are fixed, the temperature of exothermic reaction in the optimal design scheme is larger than that in the initial design scheme, and the high-temperature heat released from the exothermic reactor increases significantly in the optimal design scheme. The enthalpy efficiency (COP) and exergy efficiency monotonously increase as the entransy efficiency increases in the optimization process. The entransy efficiency has a definite physical meaning and pays more attention to the quality of the high-temperature heat recovered by the heat pump than enthalpy efficiency: it does not introduce an additional parameter and has more succinct expression than exergy efficiency. The multi-parameter optimization approach taking entransy efficiency as the objective function is very effective in the optimization design of IAH chemical heat pump. (C) 2012 Elsevier Ltd. All rights reserved.