The aerodynamic heating environment for spacecrafts currently under development typically possesses the following characteristics:high enthalpy, high heat flux and long heating time. This in turn has lead to the shift of active research work of heat shield materials, e.g., phenolic-resin based composites, towards enhancing properties such as higher ablation resistance, good heat insulation and even lower densities. To overcome the limitation of materials’ intrinsic properties and to improve their performances, both ablative(resin based) and non-ablative(ceramic based) types of heat shield materials can be further optimized by applying functional coating materials on top of the ablation surface. This review has focused on the recent research effort on the coating material for different thermal protection systems and categorized them into two major types:ablative and non-ablative. Having obtained a comprehensive understanding about their pros and cons, a possible solution is proposed at the end of this article for resin-based ablative composites:coatings consist of silicon-based preceramic polymers that can be cured around the same temperature as phenolic resin but ceramized in-situ during flight.