Silicon carbide( SiC) – titanium diboride (TiB2) composite was prepared with boron (B) and carbon (C) as sintering additive via pressureless sintering at 2180°C. The density of sintered samples achieved 96% of full densification. The mechanical properties and electrical conductivity of composite ceramics with different SiC content were researched. The results showed that with the increasing of SiC content the hardness and electrical resistivity of composites decreased, while the strength increased. Although the XRD patterns of sintered samples showed that non new phase was produced, SEM images showed that SiC particle enlarged and surrounded by TiB2 grain during sintering. In this case the fracture mode was intergranular fracture.