Pure Al2O3/AlB12/Al composite ceramic powders have been synthesized using high frequency induction heating method. This method starts from Al and B2O3 powder mixtures, after which Al2O3/AlB12/AlN composite ceramics were fabricated by hot-press sintering at 16000C for 2h under the protection of a N2 atmosphere. The bending strength and the fracture toughness of the ceramics were measured by the three-point bending method and the indentation fracture method, respectively. The results show that the pure Al2O3/AlB12/Al composite ceramic powders can be successfully synthesized by high frequency induction heating method. Al2O3 and AlB12 phases were formed by the liquid-liquid reaction mechanism and the liquid-solid reaction mechanism, respectively. The bending strength and the fracture toughness of the Al2O3/AlB12/AlN composite ceramics were 549.48MPa and 5.96MPa.m1/2, respectively. These values are 56.99% and 49% greater than those of the pure Al2O3 ceramic (350MPa and 4MPa.m1/2).