Abstract: Choosing 7μm SiC powder as a raw material, SiC ceramics were prepared via a reaction sintering technique.Phases, microstructures, mechanical properties and fractographs of the SiC ceramics were studied.Theresults indicated that the micron SiC particles and graphite nano-particles distributed uniformly in the SiC preformsin which 3-dimensional connecting pores were formed, ensuring a fine infiltration ability of the melted Si in the SiCperforms.The reaction sintered SiC(RSSC)ceramics had a high SiC content and a low free Si content.The mainproperty values of the RSSC ceramics were the density of 3.01g·cm-3, the Rockwell hardness of 95HRA and thebending strength of 410MPa, which completely met the technological requirements of the ceramic machinery seals.