Carbon fiber-reinforced carbon matrix composites (C/C composites) have excellent properties such as specific strength and specific elastic modulus, along with excellent fatigue resistance, thermal shock resistance, ablation resistance, frictional properties, lightweight, heat/thermal conductivity, and dimensional stability. C/C composites are the materials that exhibit almost no decline in mechanical properties, even at 2000–3000 °C, when protected from oxidation. A method of directly coating the surface of the fiber, to form an oxide film on the surface of the produced composite material, and method for loading directly into the filler when producing the resin have been proposed as the method for imparting antioxidation properties typical. This chapter is a detailed review on the manufacturing methods, antioxidation properties, and applications of C/C composites.