Zirconium diboride toughened by silicon carbide and zirconia fiber (ZrB 2 SiCZrO 2f ) was prepared by using planetary ball mill and the effect of milling time was investigated. The results showed that both the length of fiber and particle size of ZrB 2 SiC-matrix were reduced as the ball milling time increased. When milling time varied from 8h to 12h, the accumulated fibers and agglomerated particles were observed. The production of a homogeneous ceramic could be successfully achieved by using a combination of 20h milling time and hot-pressing at 1850°C for 60min under a uniaxial load of 30MPa. The optimal flexural strength and fracture toughness of the hot-pressed ZrB 2 SiCZrO 2f ceramics reached 1084MPa and 6.8MPam 1/2 , respectively. The main toughening mechanisms were fiber debonding, fiber pull-out and transformation toughening. The results indicated that the ball milling technique was proposed as a potential and simple method to obtain usable quantities of ZrB 2 SiCZrO 2f ceramic.