Here, we have introduced a novel and facile method to prepare porous hollow CuO nanofibers and Cu nanofibers via single-spinneret electrospinning of polyvinyl pyrrolidone (PVP)/copper acetate (Cu(CH(3)COO)(2)) solution followed by annealing and reduction. In this approach, the diameter and the shell thickness of the fibers can be simply adjusted by the concentration of PVP and the ratio of PVP to Cu(CH(3)COO)(2). A possible mechanism is proposed to explain the formation of porous hollow CuO and Cu nanofiber. This method provides an new idea to prepare metal-oxide and metal fibers with a long continuous porous hollow morphology.