SnO2-ZnO composite nanofibers were synthesized by an electrospinning method in this study. The structural composition and morphology were characterized by X-ray diffraction, scanning electron microscopy and N-2 physical adsorption. The results indicated that hollow hierarchical SnO2-ZnO composite nanofibers having mesopore structure formed after sintering at 600 degrees C for 3 h. The gas sensor prepared by the SnO2-ZnO composite nanofibers exhibited good selectivity to methanol in the presence of ethanol, acetone, formaldehyde, ammonia, toluene and benzene at the optimum operating temperature of 350 degrees C. The response and recovery time to 10 ppm methanol were about 20 s and 40 s, respectively. The growth mechanism of the hollow hierarchical nanofibers was discussed, as well as the methanol adsorption-desorption mechanism. (C) 2013 Elsevier B.V. All rights reserved.