Cordierite-bonded porous SiC ceramics were fabricated with and without CeO 2 addition in air by an in situ reaction bonding technique. The effects of CeO 2 addition on the phase composition, microstructure and properties of porous SiC ceramics were investigated. It was found that the CeO 2 addition strongly promotes the phase transformation towards cordierite while inhibits the formation of spinel. With CeO 2 addition, the neck growth was enhanced, and the mechanical properties of porous SiC ceramics were improved. When 2.0wt.% CeO 2 was added, a flexural strength of 35.3MPa was achieved at an open porosity of 42.1%. Pore size distribution characterization by mercury porosimetry indicated that 2.0wt.% CeO 2 addition enlarged the average pore size of porous SiC ceramics and introduced a bigger homogeneity in pore size. In addition, it was found that higher permeability was obtained after adding 2.0wt.% CeO 2 . Moreover, the thermal shock resistance of cordierite-bonded porous SiC ceramics was also improved by the addition of CeO 2 .