ZrB 2 –SiC composites were prepared by spark plasma sintering (SPS) at temperatures of 1800–2100°C for 180–300s under a pressure of 20MPa and at higher temperatures of above 2100°C without a holding time under 10MPa. Densification, microstructure and mechanical properties of ZrB 2 –SiC composites were investigated. Fully dense ZrB 2 –SiC composites containing 20–60mass% SiC with a relative density of more than 99% were obtained at 2000 and 2100°C for 180s. Below 2120°C, microstructures consisted of equiaxed ZrB 2 grains with a size of 2–5μm and α-SiC grains with a size of 2–4μm. Morphological change from equiaxed to elongated α-SiC grains was observed at higher temperatures. Vickers hardness of ZrB 2 –SiC composites increased with increasing sintering temperature and SiC content up to 60mass%, and ZrB 2 –SiC composite containing 60mass% SiC sintered at 2100°C for 180s had the highest value of 26.8GPa. The highest fracture toughness was observed for ZrB 2 –SiC composites containing 50mass% SiC independent of sintering temperatures.