Herein, large-scale uniform flowerlike SnO2 bundles that built by numerous one-dimensional tetragonal prism nanorods were synthesized by a simple hydrothermal method with the help of the poly(ethylene glycol) (PEG). Further investigation of the formation mechanism reveals that the PEG-assisted hydrothermal process is vital to the formation of the better complex nanostructures. The sensors fabricated from the flowerlike SnO2 nanorods bundles exhibited the sensitivity of 12.4 for 50 ppm of ethanol at reduced working temperature (300 degrees C). Moreover, a linear dependence of the sensitivity on the ethanol concentration was observed, which suggests that the flowerlike SnO2 nanorods bundles are very suitable to detect ethanol with low concentration. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.