SiC/C composites were prepared from a mixture of polycarbosilane and phenolic resin with weight ratio of 2/1 and 1/1 using PVB as a binder. The two types of green bodies which were formed by mould pressing method were treated in the temperature range from 1,000℃ to 1,500℃ under nitrogen. X-ray diffraction patterns, density, flexural strength and fracture surfaces of the composite were examined. The flexural strength of the composites at room temperature increased with heat-treatment temperature and showed a maximum value of 175 MPa at 1,300℃. When the composite was heat treated at 1,400℃, the flexural strength decreased rapidly due to the crystallization of SiC. The SiC/C composites showed good oxidation resistance up to 830 ℃. The effective mixing ratio of PCS/phenolic resin to obtain improved mechanical property was 2/1.