Aqueous solutions of metallic salts, ZrO(NO3)2.2H2O and Y(NO3)3.5H2O were used as raw materials to synthesize crystalline submicron spherical powders of Zr0.94Y0.06O1.97 with tetragonal crystal phase. Each aqueous solution was mixed on the magnetic stirrer to homogenize for 12 hours. The concentration of the mixed solutionwas changed from 0.01mol/$ell$ to 0.1mol/$ell$ calculated as the concentration of Zr0.94Y0.06O1.97. Ultrafine droplets of starting mixed solution were sprayed by the ultrasonic vibrator and carried into the furnace kept at 55$0^{circ}C$, $650^{circ}C$, 75$0^{circ}C$ and 85$0^{circ}C$ using carrier gas of air (10$ell$/min) and pyrolysed to form Y-TZP fine powders. The results of this exeriment were as follows. 1) Synthesized powders were nonagglomerated and spherical type. 2) Particle size distribution was narrow between 0.1${mu}{ extrm}{m}$ and 1${mu}{ extrm}{m}$. 3) Forming reaction Y-TZP was finished above synthetic temperature 75$0^{circ}C$. 4) As the synthetic temperature rised from 55$0^{circ}C$ to 85$0^{circ}C$, the mean particle size decreased from 0.35${mu}{ extrm}{m}$ to 0.22${mu}{ extrm}{m}$ in the concentration of starting solution with 0.02mol/$ell$. 5) At 75$0^{circ}C$ of synthetic temperature, the concentration changes of starting solution from 0.01mol/$ell$ to 0.1mol/$ell$ increased the mean particle size from 0.24${mu}{ extrm}{m}$ to 0.38${mu}{ extrm}{m}$. 6) Chemical compositions of each synthesized particle were homogeneous nearly.