In this study, we investigated the effect of aluminum species on hydrogen adsorption on carbon nanotube (CNT). This hydrogen absorption mechanism has been clarified by potential energy analysis and molecular-dynamics simulations. There were potential barriers in both reactions, absorption and dissociation of hydrogen on the surface of CNT. These activation energies were, however, certainly decreased by aluminum species. Furthermore, chemical and physical properties of the electronic structures were analyzed by kinetic energy density, tension density, and stress tensor density.