The continuous SiC fiber reinforced ceramic matrix composites have been used for various applications that require high strength at elevated temperature and oxidation resistance. In this study, PIP (polymer impregnation and pyrolysis) process was used to produce SiCf/SiOC composites, and polysiloxane resin was used as matrix precursor. A platinum catalyst was added to polysiloxane to improve the manufacturing process. The ceramic yield and crosslinking of polysiloxane were examined using TGA (thermogravimetric analysis) and DSC (differential scanning calorimetry) analysis. The ceramic yield of polysiloxane increased with addition of catalyst, and the optimum amount of catalyst was determined by analyzing the effects of catalyst amount on polysiloxane resin. The addition of catalyst did not affect the mechanical and dielectric properties of SiCf/SiOC composites.