Necklace-like In2O3 nanowires, which consist of In2O3 crystals (beads) and nanowires (thread), demonstrated by a simple thermal method. The shape of bead crystals based on an (111)-octahedron, of which vertices are truncated with (100) facets. According to the growth direction of the nanowires, the truncated octahedron has two different shapes; i.e., symmetric one on < 100 >-nanowires and asymmetric one on < 111 >-nanowires. It is shown that the growth of the bead crystals is determined by anisotropy of the growth rates of low-index facets related to their surface energy and an epitaxial relationship between the bead crystals and nanowires. Their formation mechanism and photoluminescence are discussed. (C) 2011 Elsevier B.V. All rights reserved.