The effect of $Al_2O_3+Y_2O_3$ additives on fracture toughness of ${eta}-SiC-TiB_2$ composites by hot-pressed sintering was investigated. The ${eta}-SiC-TiB_2$ ceramic composites were hot-press sintered and pressureless-annealed by adding 16, 20, 24 wt% ${eta}-SiC-TiB_2$(6:4 wt%) powder as a liquid forming additives at low temperature(1800 $^{circ}C$) for 4 h. Phase analysis of composites by XRD revealed mostly of ${alpha}$-SiC(6H), $TiB_2$, and YAG($Al_5Y_3O_{12}$). The relative density was over 95-88 % of the theoretical density, and the porosity increased with increasing $Al_2O_3+Y_2O_3$ contents because of the increasing tendency of pore formation. The fracture toughness showed the highest value of 5.88 MPa${cdot}m^{1/2}$ for composites added with 20 wt% $Al_2O_3+Y_2O_3$ additives at room temperature. The electrical resistivity showed the lowest value of $5.22{ imes}10^{-4};{Omega};{cdot};cm$ for composite added with 20 wt% $Al_2O_3+Y_2O_3$ additives at room temperature, and was all positive temperature coefficeint resistance(PTCR) against temperature up to 900 $^{circ}C$