20% Er₂O₃-stabilized Bi₂O₃ (ESB) nano?bers were prepared through electrospinning followed by calcination. The phase structures, morphology and electrical conductivities of the nano?bers have been investigated. The results show that the monoclinic phase (α) and tetragonal phase (β) coexisted in the un-doped Bi₂O₃ nanofibers, however, the cubic (c) phase could be stabilized in Bi₂O₃ nano?bers when Er₂O₃ doped in the sample. What’s more, the 500℃ and 600℃ calcined ESB nanofibers possessed high length–diameter ratio, uniform morphology and relatively smooth surfaces. An high oxide ion conductivity of the nano?bers was observed at 500℃, which is about 0.03 S?cm_-1.