SnO2 nanofibers with and without block copolymer P123 (EO20PO70EO20) in the precursor are synthesized via a simple electrospinning method. The Brunauer-Emmett-Teller surface areas of the nanofibers; with and without P123 are 113.261 and 18.025m(2)g(-1), respectively. Gas sensing properties of these two samples are investigated by exposing the corresponding sensors to NH3, C2H5OH, and CH3COCH3 at 280, 300, and 340 degrees C, respectively. Comparing with nanofibers without P123, the SnO2 nanofibers with P123 hold enhanced response value, higher saturated-detection-concentration, and lower minimum-detection-limit. The response is 59, 75, and 65 for nanofibers with P123 to 500ppm NH3, C2H5OH, and CH3COCH3, respectively, and is 28,50, and 43 fornanofibers without P123. The minimum-detection-limit is 5, 1, and 1 ppm for nanofibers with P123 to detect NH3, C2H5OH, and CH3COCH3, respectively, and is 50, 20, and 10 ppm for nanofibers without P123. The improved gas sensing properties are based on their coarse and loose morphology and higher Brunauer-Emmett-Teller surface area brought by adding P123 (C) 2009 Elsevier B.V. All rights reserved