The　resonant　chaotic　dynamics　of　a　symmetric　cross-ply　composite　laminated　plate　are　studied　using　the　exponential　dichotomies　and　an　averaging　procedure　for　the　first　time.　The　partial　differential　governing　equations　of　motion　for　the　symmetric　cross-ply　composite　laminated　plate　are　derived　by　using　Reddy＇s　third-order　shear　deformation　plate　theory　and　von　Karman　type　equation.　The　partial　differential　governing　equations　of　motion　are　discretized　into　two-degree-of-freedom　nonlinear　systems　including　the　quadratic　and　cubic　nonlinear　terms　by　using　Galerkin　method.　There　exists　a　fixed　point　of　saddle-focus　in　the　linear　part　for　two-degree-of-freedom　nonlinear　system.　The　Melnikov　method　containing　the　terms　of　the　nonhyperbolic　mode　is　developed　to　investigate　the　resonant　chaotic　motions　of　the　symmetric　cross-ply　composite　laminated　plate.　The　obtained　results　indicate　that　the　nonhyperbolic　mode　of　the　symmetric　cross-ply　composite　laminated　plate　does　not　affect　the　critical　conditions　in　the　occurrence　of　chaotic　motions　in　the　resonant　case.　When　the　resonant　chaotic　motion　occurs,　we　can　draw　a　conclusion　that　the　resonant　chaotic　motions　of　the　hyperbolic　subsystem　are　shadowed　for　the　full　nonlinear　system　of　the　symmetric　cross-ply　composite　laminated　plate.