Undoped and 0.2-1.0 mol% Rh-doped SnO2 nanofibers were fabricated using electrospinning combined with calcination treatment. The fibrous morphology of these nanofibers were maintained and the grain size of the SnO2 nanocrystals were greatly decreased after Rh doping. Sensors based on these nanofibers were fabricated through a hot pressing mathod. The gas sensing properties of these nanofibers were investigated systematically. The results indicated that the response to 50 ppm acetone of 0.5 mol% Rh doped SnO2 nanofibers was 60.6, which was 9.6 times higher than that of undoped SnO2 nanofibers. In addition, the Rh-doped SnO2 nanofibers showed a decreased cross-response to ethanol, whereas pure SnO2 naofibers did not show selective detection of ethanol and acetone gases. The doping of Rh ions into SnO2 nanocrystals modulates the electron concentration, and induces the changes of the oxygen vacancies and chemisorbed oxygen of SnO2 naofibers. Thus, the doping of Rh3+ into SnO2 nanofibers should be a promising method for designing and fabricating acetone gas sensor with high gas sensing performance. (C) 2017 Elsevier B.V. All rights reserved.