In order to increase the yield of the ceramic precursors, copolymers of polycarbosilane(PCS) and γ-methacryloxypropyltrimethoxy silane (γ-MPS) were synthesized by hydrosilylation with platinum catalyst. The structures of PCS-co-MPS ceramic precursors were investigated by using FT-IR and ¹H-NMR spectrometers. The syntheses of ceramic precursors were confirmed by monitoring the change of the absorption bands appearing at 2100, 1720, 1640, 1170, 1130 cm^-1 on the FT-IR spectra. The syntheses of eramic precursors were also confirmed by the presence of peaks at 4.1, 3.5, 1.8 ppm on the ¹ H-NMR spectra. The conversion of PCS-co-MPS copolymers was around 87.5% and 18.2% higher than that of the pure PCS. After the heat-treatment at 1500 ℃, the crystalline peaks for β-Sic were observed at-60, -109, ppm on the²⁹ Si-NMR spectra, and at 2θ=35°, 59° and 71° on the X-ray spectra, respectively. It showed the conversion of ceramic precursors to crystalline β-SiC.