In this letter, pure and 10% (mol) Ni-doped In2O3 nanofibers were prepared by an electrospinning method and characterized by differential thermal analyse (DTA), thermal gravimetric analyse (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) etc. The fibers after calcining at 600 degrees C for 4 h belong to cubic structure. SEM images exhibited that the nanofibers had an average diameter of about 100 nm and are several tens of microns long. The NO2 sensing properties based on these fibers at 95 degrees C were also investigated. In the low concentration range (5-150 ppm), the Ni-doped sensor exhibited excellent linear dependence. Moreover, good selectivity was also observed in our investigations.