Our previous study has shown that an effective tritium permeation barrier (TPB) with Al2O3 layer found could be obtained by oxidization of a Fe-Cr-Al ferritic steel. In this study, irradiation effects on deuterium permeation behavior through oxidized Fe-Cr-Al terrific steel (OFFS) have been investigated by Au ions irradiation followed by deuterium gas driven permeation (GDP) experiments. The deuterium permeability of the irradiated and original OFFS samples has been obtained and compared. Oxide layer has been characterized by Xray photoelectron spectroscopy (XPS) experiment and scanning electron microscopy (SEM) experiment. The defects in the oxide layer with and without Au ions irradiation have been characterized by Doppler broadening spectrometry of positron annihilation (DBS-PA) experiments. The deuterium permeation behavior of OFFS changed owing to the Au ions irradiation, which could be attributed to the increased density of vacancy-type defects. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.