Uniaxially aligned In ₂O ₃ nanofibers are prepared by magnetic-field-assisted electrospinning method. The average diameter of the gained nanofibers is about 90 nm. The optimum operating temperature of the sensor based on the uniaxially aligned In ₂O ₃nanofibers to ethanol is 120°C, the response and recovery times of the sensor are 0.4 s and 3 s, respectively. Compared with the randomly deposited nanofibers, the uniaxially aligned nanofibers show much rapider response.