We have carried out first-principle calculations of simple models for Al nanowire wrapped in carbon nanotube and have investigated the electronic properties of them based on the regional density functional theory. For both the (8,0) zigzag nanotube-wrapped and the (4,4) armchair nanotube-wrapped Al nanowire models, the nanowire with a monoatomic thickness is stabilized just on the center axis of the carbon nanotube due to a shortage of the tube radius. The microscopic image that electrons in the At nanowire interact with the electrons in the nanotube on every side is obtained clearly in terms of the quantum energy densities. Band structures of the nanotube-wrapped Al nanowire models represent the conductivity along the wire, where bands originated from the At atom raise and cross the Fermi level for each model. We have confirmed that reversible hydrogen storage processes are realized in our model. Under the external electric field and current, the effective charge tensor density of the Al atom has been computed using the non-relativistic limit of quantum electrodynamics. (C) 2004 Elsevier Ireland Ltd. All rights reserved.