In this study, it is demonstrated that operation of dead-ended anode fuel cell at high temperature and pressure reduce the durability of membrane electrode assembly. In such a way that after 9000 degradation cycles, the maximum power density under H-2/O-2 gas feed mode for the aged MEA at high temperature and pressure is dropped by 38.8%. While the maximum power density drop is 27.1% for the aged MEA at low temperature and pressure. Comparison of the electrochemical impedance spectroscopy responses of MEAs shows that during aging process, the charge transfer resistance increase rate is more at higher temperature and pressure. This suggests the more severe destruction of catalyst layer at higher temperature and pressure and is in agreement with the obtained values of electrochemical surface area from the cyclic voltammetry test. In addition, the transmission electron microscopy and scanning electron microscopy images show the further degradation of cathode catalyst layer and more sever Pt agglomeration at higher temperature and pressure. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.