Zirconia nanofibers were fabricated by the sol-gel combined with an electrospinning process. The spinnable sol was prepared with zirconium carbonate and acetic acid as raw materials, yttrium nitrate as phase stabilizer, and polyvinyl pyrrolidone as spinning aid. Formation mechanism of spinnable sol was studied. The possible structure of Poly zirconium acetate (PZA) and idealized formation process of PZA were researched in this mechanism. Electrospinning process and heat-treatment process were also researched. Being heat-treated to 1200 degrees C, the fibers with diameters of 400-600 nm are composed of 20-40 nm tetragonal zirconia grains, which is crack free with smooth surface. (C) 2015 Published by Elsevier B.V.