Several thermal protective systems of hypersonic vehicles were reviewed. The aero鄄thermal character鄄 istics of sharp leading edge and the trend of the corresponding thermal protective materials on hypersonic air鄄breathing vehicles were analyzed. The research programs including Hytech, X43A and NGLTH which were proposed in recent twenty years in USA were introduced. The development of sharp leading edge materials and the correlative aero鄄heat鄄 ing tests were described in detail.