Based　on　the　non-autonomous　ordinary　differential　governing　equations,　global　dynamical　analysis　of　a　parametrically　and　externally　excited,　simply　supported　rectangular　thin　plate　is　given　by　high　dimensional　Melnikov　method.　In　the　formulas　of　the　thin　plate,　the　case　of　buckling　of　the　plate　is　considered.　Numerical　simulations　verily　the　analytical　predictions.