Indium oxide (In2O3) nanobelts have been fabricated by thermal evaporation of metallic indium powders with the assistance of Au catalysts. The as-synthesized nanobelts are single-crystalline In2O3 with cubic structure, and usually tens of nanometers in thickness, tens to hundreds of nanometers in width, and several hundreds of micrometers in length. The room temperature photoluminescence spectrum of In2O3 nanobelts features a broad emission band at 620 rim, which could be attributed to oxygen deficiencies in the as-synthesized belts. The formation of In2O3 nanobelts follows a catalyst-assistant vapor-liquid-solid growth mechanism, which enables the controlled growth of individual belts on predetermined sites. (c) 2006 Elsevier B.V. All rights reserved.