The mechanical and electrical properties of the hot-pressed and annealed ${eta}-SiC-TiB_2$, electroconductive ceramic composites were investigated as function as functions of the liquid forming additives of $Al_2O_3+Y_2O_3$. The result of phase analysis of composites by XRD revealed ${alpha}$-SiC(6H), $TiB_2$,/TEX>, and YAG($Al_5Y_3O_{12}$) crystal phase. The relative density and the mechanical properties of composites were increased with increasing $Al_2O_3+Y_2O_3$ contents in pressureless annealing method because YAG of reaction between $Al_2O_3$ was increased. The flexural strength showed the highest value of 458.9 MPa for composites added with 4 wt% $Al_2O_3+Y_2O_3$ additives in pressed annealing method at room temperature. Owing to crack deflection, crack bridging, phase transition and YAG of fracture toughness mechanism, the fracture toughness showed 7.1 MPa ${cdot};m^{1/2}$ for composites added with 12 wt% $Al_2O_3+Y_2O_3$ additives in pressureless annealing method at room temperature. The electrical resistivity and the resistance temperature coefficient showed the lowest value of $6.0{ imes}10^{-4};{Omega};{cdot};cm(25'^{circ}C}$ and $3.0{ imes}10^{-3}/^{circ}C$ for composite added with 12 wt% $Al_2O_3+Y_2O_3$ additives in pressureless annealing method at room temperature, respectively. The electrical resistivity of the composites was all positive temperature coefficient resistance(PTCR) in the temperature ranges from 25 $^{circ}C$ to 700 $^{circ}C$