isothermal compression of hydrogenated Ti-6Al-4V alloy was carried out on a Thermecmaster-Z simulator at deformation temperatures between 760 and 920 degrees C, constant strain rate between 0.01 and 10.0s(-1), and a maximum height reduction of 60%. The high temperature deformation behavior of hydrogenated Ti-6Al-4V alloy was characterized based on an analysis of the stress-strain behavior, kinetics, and processing map. The smallest activation energy for deformation obtained in isothermal compression of hydrogenated Ti-6Al-4V alloy is 208.3 kJ/mol in the two-phase region of Ti-6Al-4V alloy with hydrogen contents of 0.2 wt%. Three unstable deformation regions were obtained by constructing the processing map of hydrogenated Ti-6Al-4V alloy with hydrogen contents of 0.2 wt%. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.