In this work, pure and 1-5 mol% Co-doped SnO2 nanofibers were synthesized via an electrospinning method. The morphological and microstructural properties of these nanofibers were obviously changed and the grain size of the SnO2 nanocrystal were greatly decreased by Co doping. Sensors based on these nanofibers were fabricated after a hot pressing process on the ceramic plates. The gas-sensing properties of pure and Co-doped SnO2 nanofibers were tested to several kinds of Volatile Organic Compounds (VOCs). The results indicated that among all the samples (0, 1, 3 and 5 mol% Co-doped SnO2 nanofibers), 3 mol% Co-doped SnO2 nanofibers showed the highest response toward 100 ppm ethanol, having a response of 40.1, which was over 4 times higher than pure SnO2 nanofibers. At the same time, the sensors based on 3 mol% Co-doped SnO2 nanofibers also exhibited good repeatability and long term stability, which were promising for designing ethanol gas sensor with high performance. (C) 2016 Elsevier B.V. All rights reserved.