ZnO nanorod array thin film with Al-doping and hydrogen treatment was developed as a photoelectrode combining the functions of transparent conducting oxide thin film and photoactive 1-dimensional nanostructured semiconductor into a single layer for photo-electrochemical water splitting. It was demonstrated that hydrogen treatment and Al-doping enhanced the dark currents, photocurrents, and hydrogen generation efficiencies largely and the enhancement by hydrogen treatment was more significant. The maximum photoinduced hydrogen generation efficiency was about 0.020%. Furthermore, hydrogen treatment also improved the photosensitivity and the stability under illumination significantly. The minimum decay time constant and rise time constant were 1.71 and 1.22 s, respectively. And after current-voltage scanning upon illumination for 50 cycles, the 1-dimensional morphology still remained unchanged but those without Al-doping and/or hydrogen treatment were altered seriously. The good photoresponse and stability made the Al-doped ZnO nanorod array thin film with hydrogen treatment have wide applications in the photoelectrochemical field. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.