Tin oxide (SnO 2 ) nanowires have been synthesized in bulk quantities at lower temperature (680 o C) by thermal evaporation of SnO powder. These as-synthesized SnO 2 nanowires are single crystals with [301] growth axis, with diameters ranging from 10 to 190 nm and lengths extending to tens of micrometers. The growth of SnO 2 nanowires synthesized by lower-temperature evaporation is dominated by a self-catalytic vapor-liquid-solid (VLS) mechanism. The self-catalytic effect in VLS process has been described.