The yield of vinylsilane-polycarbosilane ceramic precursors was increased with the increase of reaction temperature, concentration of monomer and catalyst. It was also observed that the molecular weight of ceramic precursor was increased with vinyl contents in the PCS. It was found that the ceramic precursors of vinylsilane-polycarbosilane were synthesized from the absorption peak of 2100㎝^(-1), Si-H bond, to decrease and the peak of 1600㎝^(-1), C=C bond, to increase with reaction by FT-IR, spectrometer. It was observed that organic structure of the β-SiC was converted to crystalline structure over 1000℃ with pyrolysis.