ZnO:Tb nanofibers are fabricated by electrospinning method. X-ray diffraction and Raman results show that the sample is of hexagonal phase. The positions of doped diffraction peaks shift toward the small angle and the shift does not change with Tb content. Photoluminescence (PL) spectra of Tb-doped ZnO nanofibers show a strong defect-related emission and indicate that the doping affects the crystallinity of ZnO. It is found that Ti-capped can enhance the ultraviolet emission of ZnO nanofiber, while the defect-related emission is depressed. The enhancement in ultraviolet emission is mostly attributed to the surface plasmon coupling effect at the interface. The PL results indicate that the ZnO is not a proper matrix for Tb3+ ion.