Phase transition of molybdenum nanowires confined in a low-dimensional nanospace is investigated by molecular dynamics simulation focusing on confinement and Gibbs-Thomson effects. The concentric nanowire is mainly formed in the nanospace with radius of 3 nm or less and the crystalline nanowire becomes dominant for the case of larger radius. The energy difference between concentric and crystalline structures was only 61 meV/atom, which induces structural transition easily. The melting point was negatively proportional to the inverse of nanowire radius due to the Gibbs-Thomson effect, whereas the solidification point of thin nanowires was almost same due to the confinement effect. (c) 2012 Elsevier B.V. All rights reserved.