In order to increase the toughness of ZTA(zirconia toughened alumina) ceramics, the present study focused on rearrangement and densification of particles according to the particle size of the parent material. When rough alumina was used for production of ZTA, densification behavior was observed in the specimen sintered at a temperature over 1550 oC. However, it was found that the densification behavior was occurred in the specimen sintered at 1450 oC when fine alumina powder was used. High relative density exceeding 98% was obtained when fine alumina powder was mixed with 15 wt% of 3Y-TZP and sintered at 1600 oC. Also, a hardness of 1820.2 Hv was obtained when a specimen containing 10 wt% of 3Y-TZP was sintered at 1600 oC. In the case of 3Y-TZP containing rough alumina powder that had been sintered the hardness value was around 1720.3 Hv. It was predicted that an improved toughening effect in ZTA could be achieved by using finer alumina powder as the parent material.