ZrO2 precursor powders containing 3% Y2O3 were prepared via a single emulsion processing route and a double emulsion processing route. In both routes xylol was used as the oil phase,span-80 as the surfactant,and an aqueous solution containing zirconium or ammonia as the water phase. The calcination of the precursor powders was performed at 600 ℃ for 2 h,leading to tetragonal phase ZrO2 nanometer powders. The ZrO2 powders and the precursor powders were analyzed and characterized by means of TGA-DTA,XRD,TEM,BET and laser particle size analyser. The results indicate that xylol-span-80-water phase system contain more water phase,which to a certain extent overcomes the disadvantages of low output by emulsion route in preparing powders. The best volume ratio Vxylol∶Vspan-80∶Vwater= 95∶5∶25 leads to the attaining of powders. The special tetragonal phase powders with less agglomeration were prepared via either the single emulsion processing route or the double emulsion processing route according with the ratio. But compared to the single emulsion processing route,the powders prepared via the double emulsion processing route display smaller particles with more even size distribution,the average size of around 15 nm.