Pure and Pr-doped (2 wt%, 8 wt%) ZnO nanostructures are synthesized by an electrospinning method and followed by calcination. The as-synthesized nanostructures are characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and static gas sensor testing device. Pure and Pr-doped ZnO nanostructure exhibited hexagonal ZnO lattice structure and another Pr7O12 phase is detected in the 8 wt% Pr-doped ZnO nanofibers. The surface morphology of pure ZnO and 8 wt% Pr-doped ZnO is nanofiber linked by nanosized ZnO grains. The surface morphology of 2 wt% Pr-doped ZnO is spherical nano-ZnO crystal-like island. Comparing with pure ZnO nanofibers, Pr-doped ZnO nanostructure exhibit improved acetic acid sensing properties at 380 C. 8 wt% Pr-doped ZnO nanofiber shows a high selectivity in detecting acetic acid, acetone and methanal. Pr-doped ZnO sensors show different optimal operating temperature with different concentration of Pr. (C) 2013 Elsevier B.V. All rights reserved.