Mesoporous silicon carbide SiC ceramics were produced via the pyrolysis of polycarbosilane PCS with and without SiC nano sized particle filler, and their pore characteristics such as size and BET surface area were investigated. The amount of filler and the pyrolysis temperature significantly affected the surface area and pore size. The surface area of PCS reached around 0.5 m 2 g by the pyrolysis at 800c C and pore also was found to almost disappear. In contrast, the specimen with filler showed high surface area above 200 m 2 g after the pyrolysis at 800c C and the retention of mesopore even after the pyrolysis at 1200c C.