Functionally graded materials (FGM) are a kind of inhomogeneous composites which usually made from a mixture of metals and ceramics.Their material properties exhibit a smooth and continuous change from one surface to another by gradually changing the volume fraction of constituent materials artificially.The use of FGM has attracted much interest in many engineering applications as heat-shielding materials such as aircraft, aerospace.For example, in hypersonic air flow the plates and shells structures used in spacecraft may subject serious dynamic problems, such as nonlinear flutter.To the best of the authors knowledge, the researches about nonlinear flutter of the FGM structures are rare.The aim of this paper is to study nonlinear aerothermoelastic flutter of functionally graded materials cylindrical shell in hypersonic air flow.It is assumed that the constituents of the shell are temperature-dependent metal and ceramic and graded in thickness direction by a simple power law.In order to obtain the governing equation of motions, Reddys third shear deformation theory, yon Karman nonlinear strain-displacement relations and Hamiltons principle are used.The third piston theory and steady state aerodynamic heating are considered to calculate aerothermoelastic properties.The influence of all kinds parameters on the flutter behavior of the shell are discussed numerically.