Abstract: Solvent extraction of Zr(IV) with TBP in kerosene was used to precipitate precursory zirconia which was then processed to produce ultrafine zirconia powders. The powder prepared was examined and characterized with transmission electron microscopy (TEM) and X-ray diffraction (XRD). Effects of the conditions of preparation on powder properties were especially investigated.It was found the preclpitate was gel-like material with heterogeneous porosity. The gel transformed to polycrystalline particles when calcined to ultrafine powder at 600℃. The composition of the loaded organic phase and the conditions of washing the precipitate are two main factors affecting the properties of powder obtained