We investigated the thermal behavior of titanium hydride with different particle size at the different atmospheres using the thermal analysis techniques. The results demonstrated that the smaller particle has larger reactivity and showed less stable at higher heating rates. Even in the thermal plasma with inert atmosphere, titanium hydride was partially oxidized and an effective oxidation occurs in thermal plasma reactor with oxygen as reactive gas. Milling process changed the stoichiometry of titanium hydride from TiH2 to TiHy and the amount of hydrogen in titanium hydride affects its oxidation behavior. (C) 2012 Elsevier B.V. All rights reserved.