ZrB 2–SiC composites were fabricated by spark plasma sintering (SPS) using TaSi 2 as sintering additive. The volume content of SiC was in a range of 10–30% and that of TaSi 2 was 10–20% in the initial compositions. The composites could be densified at 1600 °C and the core–shell structure with the core being ZrB 2 and the shell containing both Ta and Zr as (Zr,Ta)B 2 appeared in the samples. When the sintering temperature was increased up to 1800 °C, only (Zr,Ta)B 2 and SiC phases could be detected in the samples and the core–shell structure disappeared. Generally, the composites with core–shell structure and fine-grained microstructure showed the higher electrical conductivity and Vickers hardness. The completely solid soluted composites with coarse-grained microstructure had the higher thermal conductivity and Young's modulus.