Global　dynamics　of　a　simply　supported　functionally　graded　materials　(FGM)　rectangular　plate　are　studied　using　the　extended　Melnikov　method　for　the　first　time.　The　FGM　plate　is　subjected　to　the　transversal　and　in-plane　excitations.　Material　properties　are　assumed　to　be　temperature-dependent.　A　twodegree-of-freedom　nonlinear　system　governing　equations　of　motion　for　the　FGM　rectangular　plate　is　derived　using　the　Hamilton＇s　principle　and　the　Galerkin＇s　method.　The　averaged　equations　are　obtained　by　the　method　of　multiple　scales.　After　transforming　the　averaged　equations　into　a　standard　form,　the　extended　Melnikov　method　is　employed　to　show　the　existence　of　multi-pulse　chaotic　dynamics.　Numerical　simulations　illustrate　that　there　exist　chaotic　responses　for　the　FGM　rectangular　plate.　©　2011　IEEE.