The phase structures and hydrogen absorption-desorption properties of Ti-25V - xCr - (35 - x)Mn alloys were investigated. It was found that the increase of Cr content in the alloys is effective for obtaining a single BCC-phase structure, which results in an increasing hydrogen capacity and a flat hydrogen sorption plateau. The plateau slope of hydrogen sorption in the Ti-25V - xCr-(35 - x)Mn system is closely correlated with the strain energy of interstitial site, exhibiting minima at x = 10 at which concentration a well-defined plateau is formed. The maximum and effective hydrogen storage capacities among studied alloys are 3.99 and 2.44 wt%, respectively. (C) 2004 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.