The electrical conductive mechanism and temperature dependence of electrical resistivity of $alpha-SiC-ZrB_2$ composites with $ZrB_2$ contents were investigated. The electrical resistivity of hot-pressed composites was measured by the Pauw method form $25^{circ} to 700^{circ}C$. The electrical resistivity of the composites follow the electrical conduction model for a homogeneous mixture of two kind of particles with different conductivity. Also, the electrical resistivity versus temperature curves indicate the formation of local chains of $ZrB_2$ particles. In case of $alpha-SiC-ZrB_2$ composites containing above 39vol.% $ZrB_2$ showed positive temperature coefficient resistance(PTCR), whereas the electrical resistivity of $alpha-SiC-21vol.% ZrB_2$ showed negative temperature coefficient resistance(NTCR).