Since more than twenty five years, composite materials have been with continuously increasing spatial and aeronautical applications requirements. The thermostructural composites materials are of utmost importance for satisfying the needs of mechanical and thermal characteristics at very high temperature and in severe environments. This paper deals with a large variety of applications concerning the aerospace and nuclear applications like nozzles and hot gas valves for Solid Rocket Motor (SRM), brake disks for planes, aerospace turbine engine exhaust nozzles, thermal protection system for reentry vehicles, but also Divert and Attitude Control System (DACS) for interceptors, heat exchangers for hypersonic propulsion systems, plasma facing components for nuclear fusion applications and special components for nuclear fission applications. We will see that Carbon/Carbon and Ceramic Matrix Composites are leading candidate materials for these hightemperature structural applications. This lecture will identify the current state-of-the-art and new technological developments. A description of the main steps of the manufacturing processes will be made.