Electrospinning technique was used to fabricate PVP/Ce(NO3)3 composite mierofibers. Different morphological CeO2 nanofibers were obtained by calcination of the PVP/Ce(NO3)3 composite microfibers and were characterized by scanning electron microscopy (SEM),Transmission electron microscopy (TEM), X-ray diffraction (XRD), thermal gravimetric and differential thermal analysis (TG-DTA), and (FHR). SEM micrographs indicated that the surface of the composite fibers was smooth and became coarse with the increase of calcination temperatures. The diameters of CeO2 hollow nanofibers (300 nm at 600 ℃ and 600 nm at 800 ℃) were smaller than those of PVP/Ce(NO3)3 composite fibers (1-2 μm). CeO2 hollow nanofibers were obtained at 600 ℃ and CeO2 hollow and porous nanofibers formed by nanoparti-ties were obtained at 800 ℃. The length of the CeO2 hollow nanofibers was greater than 50 μm. XRD analysis revealed that the composite microfibers were amorphous in structure and CeO2 nanofibers were cubic in structure with space groupO5H-FM3m when calcination tem-peratures were 600-800 ℃. TG-DTA and FTIR revealed that the formation of CeO2 nanofibers was largely influenced by the calcination temperatures. Possible formation mechanism of CeO2 hollow nanofibers was proposed.