An　analysis　on　the　nonlinear　dynamics　of　an　FGM　plate　in　hypersonic　flow　subjected　to　an　external　excitation　and　uniform　temperature　change　is　presented　in　this　article.　Material　properties　of　the　constituents　are　assumed　to　be　temperature-dependent　and　the　effective　properties　of　FGM　plate　are　graded　in　thickness　direction　according　to　a　simple　power　law　function　in　terms　of　the　volume　fractions.　Based　on　vonKarman　type　nonlinear　strain-displacement　relationship,　the　nonlinear　governing　equations　of　motion　are　derived　by　using　Hamilton＇s　principle.　Galerkin＇s　method　is　then　utilized　to　discretize　the　governing　partial　equations　to　a　two-degree-of-freedom　nonlinear　system,　including　the　quadratic　and　cubic　nonlinear　terms.　A　third-order　piston　theory　is　applied　for　the　hypersonic　aerodynamic　load.　The　Mach　number　and　in-plane　loading　are　used　as　bifurcation　parameters.　Numerical　results　including　the　bifurcations,　waveform,　phase　plots,　and　Poincare　maps　are　presented,　for　an　FGM　plate　to　show　the　influences　of　material　gradient　index,　Mach　number,　and　in-plane　load　on　the　nonlinear　dynamics.