Uniaxially aligned In2O3 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 In2O3 nanofibers to ethanol is 120 degrees 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.