In this research, high-density alumina ceramic (99 % alumina) was prepared by isostatic pressing process. The characteristics of in-process materials and final products were investigated. The forming pressure and sintering temperature term used in the experiment were 100-250 MPa and 1500-1650 ℃, respectively. Density, grain size, compressive strength, hardness and abration loss of specimens were measured. The experimental results showed that the forming porming pressure influenced on density and particle arrangement of green compact : the higher the pressure used had been, the higher the particles were compact. The sintering temperature significantly on grain size and mechanical properties of sintered specimen. The optimum sintering temperature for the preparation process was 1550 ℃. A sintered density > 99% of the theoretical density was attained. Grain size was found to be independent of density. Especially, the characteristics of high-mechanical property product are high-density and fine-grain size.