Y2O3: Eu3+ nanofibers with the average diameter of similar to 300 nm were in situ fabricated by electrospinning. X-ray diffraction (XRD) pattern confirmed that the Y2O3: Eu3+ nanofibers were composed of pure body-centered cubic (bcc) Y2O3 phase. High-resolution transmission electron microscopy (HRTEM) results indicated that Y2O3: Eu3+ nanofibers were constituted of nonspherical crystalline grains, and these crystalline grains were orderly arranged along the axial direction of single nanofiber. These Y2O3: Eu3+ nanofibers showed a partially polarized photoluminescence (PL). The arrangement of crystalline grains and the mismatch of dielectric constant between Y2O3: Eu3+ nanofiber and its environment probably contributed together to the polarized PL from Y2O3: Eu3+ nanofiber. (C) 2009 Optical Society of America