Abstract：When the hypersonic aircraft is in flight at more than Mach 4, the outer surface of the components is subjected to very high temperature due to aerodynamic heating. Then, thermal barrier and high temperature resistance materials must be developed. The functionally gradient materials (FGMs) was proposed in 1984. Thermal stresses in FGMs are explained. In this talk I will introduce: 1）Concept of Functionally Graded Materials(FGMs)，2）Steady Thermal Stress Problems in FGMs，3）Transient Thermal Stress Problems in FGMs， 4）General Treatments of Thermal Stresses in FGMs， 5）Crack Problems in the FGMs, and 6) Crack Propagation in the FGP under Thermal Shock.
