First-principles calculations were performed to investigate the bonding characteristics of the undoped and doped ZrCoH3 and predict the anti-disproportionation abilities of alloying elements (i.e. Y, V, Nb, Ta, Zr, Cr, Mn, Ru, Rh, Pd and Zn). The binding between H and Zr (or its substitute elements) shows strong ionic and weak covalent feature, and that between H and Co (or its substitute elements) displays the opposite characteristic. The H diffusion process, the size of the 8e site and the corresponding Zr-H distance were calculated, and the substitute elements of Zr (i.e. Nb, Ta and especially V) are predicted to be helpful to improve the ZrCo alloy against the hydrogen-induced disproportionation, and the substitute elements of Co may be not suitable. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.