Titanium suboxide (TiO) is one of the best catalysts which improved the hydrogen absorption-desorption property of MgH2- Mg system. The TiO catalyzed Mg MgH2 have shown a remarkably reduced apparent activation energy and enhanced the hydrogen absorption-desorption kinetics. The X-ray photoelectron spectroscopy (XPS) analysis has indicated that the oxidation state of Ti in TiO remains unchanged during ball milling and hydrogen absorption-desorption of TiO-doped-MgH2. The X-ray diffraction (XRD) analysis further confirms the XPS result. The TiO has shown the excellent catalytic effect on the Mg MgH2 system which remarkably reduced the hydrogen absorption-desorption temperatures. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.