Y2O3:Yb3+, Er3+ nanofibers were prepared by calcination of the electrospun polyvinyl pyrrolidone (PVP)/[Y(NO3)(3) + Yb(NO3)(3) + Er(NO3)(3)] composite nanofibers. For the first time, Y2O2S:Yb3+, Er3+ up-conversion luminescent nanofibers were successfully synthesized via inheritance of the morphology and sulfurization of the above electrospinning-derived Y2O3:Yb3+, Er3+ nanofibers using sulfur powders as sulfur source by a double-crucible method we newly proposed. XRD analysis indicates that Y2O2S:Yb3+, Er3+ nanofibers are pure hexagonal in structure with space group . Observation results of FESEM and TEM reveal that the diameters of Y2O2S:Yb3+, Er3+ nanofibers are 105 +/- A 13 nm, and Y2O2S:Yb3+, Er3+ nanofibers are composed of nanoparticles with the diameter ranging from 40 to 70 nm. Up-conversion emission spectrum analysis manifests that Y2O2S:Yb3+, Er3+ nanofibers exhibit strong green and red upconversion emission centering at 526, 548 and 668 nm, respectively. The green emissions and the red emission are respectively assigned to H-2(11/2)/S-4(3/2) -> I-4(15/2) and F-4(9/2) -> I-4(l5/2) energy levels transitions of Er3+ ions. The formation mechanism of Y2O2S:Yb3+, Er3+ upconversion luminescence nanofibers is also proposed. More importantly, this new strategy and fabrication technique are of universal significance to prepare other rare earth oxysulfides with various morphologies.