A wet jet milling process was employed as a novel method to prepare ceramic slurries. The wet jet milling pulverized raw materials to primary particle size within a short time. The wet jet-milled slurries showed very low viscosity, as comparing to ball-milled slurries. Moreover, the viscosity of wet jet-milled slurries was stable for long times, whereas that of ball-milled slurries increased rapidly with increase in the time. Al 2 O 3 particles after wet jet milling kept initial surface conditions, though Al 2 O 3 particles after ball milling yielded more OH groups on the surface. The relative density of the green bodies prepared from the wet jet-milled slurries was about 65% or more without depending on the solid content of slurry. On the other hand, the relative density of the green bodies fabricated by the ball-milled slurries increased with the slurry solid content, and it reached more than 60% at 50vol% of solid content.