This　paper　is　intended　to　investigate　the　nonlinear　oscillations　and　chaotic　dynamics　of　a　simply　supported　angle-ply　composite　laminated　rectangular　thin　plate　with　parametric　and　external　excitations　and　the　method　of　multiple　scales　is　presented　to　study　the　ordinary　differential　equation　of　the　system.　According　to　the　Reddy＇s　third-order　plate　theory,　the　governing　equations　of　motion　for　the　angle-ply　composite　laminated　rectangular　thin　plate　are　derived　by　using　the　Hamilton＇s　principle.　Then,　the　Galerkin　procedure　is　applied　to　the　partial　differential　governing　equation　to　obtain　a　two-degrees-of-freedom　nonlinear　system　including　the　quadratic　and　cubic　nonlinear　terms.　Such　equations　are　utilized　to　deal　with　the　resonant　case　of　1:2　internal　resonance　and　primary　parametric　resonance-1/2　subharmonic　resonance.　Furthermore,　the　stability　analysis　is　given　for　the　steady-state　solutions　of　the　averaged　equation.　Based　on　the　nonlinear　governing　equations　obtained　by　the　asymptotic　perturbation　method,　the　phase　portrait　and　power　spectrum　are　used　to　analyze　the　multi-pulse　chaotic　motions　of　the　angle-ply　composite　laminated　rectangular　thin　plate.　Under　certain　conditions　the　various　chaotic　motions　of　the　angle-ply　composite　laminated　rectangular　thin　plate　are　found.