Tungsten trioxide (WO3) nanobelts in tetragonal structure were grown on Si substrates by a hot-wall chemical vapor deposition (CVD) method without using catalysts. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, and photoluminescence (PL) spectrum. The width of the nanobelts is in the range of 50-100 nm with width-to-thickness ratios of 5-10 and lengths of up to tens of micrometers. These nanobelts grew along the [0 0 1] direction and can be identified as the tetragonal WO3 structures. Raman and PL measurements indicate the high quality of the nanobelts. The vapor-solid growth mechanism could be applicable in our experiment. (C) 2010 Elsevier B.V. All rights reserved.