In　this　paper,　the　nonlinear　vibrations　of　the　laminated　composite　piezoelectric　cantilever　plate　subjected　to　the　transverse　and　in-plane　excitations　are　investigated.　Based　on　the　Reddy＇s　third-order　plate　theory　and　von　Karman　nonlinear　strain-displacement　relation,　the　nonlinear　partial　differential　governing　equations　of　motion　are　established　for　the　laminated　composite　piezoelectric　cantilever　plate　under　combined　the　transverse　and　inplane　excitations　by　applying　Hamilton＇s　principle.　Employing　Galerkin＇s　approach,　we　discretize　the　continuous　nonlinear　dynamic　equations　of　motion　into　the　ordinary　differential　equations　with　four　modes.　Substituting　the　actual　geometric　and　physical　parameters　of　the　laminated　composite　piezoelectric　cantilever　plate　into　the　governing　equation　of　motion,　we　use　numerical　method　to　investigate　the　effects　of　the　lay-up　parameters　and　the　geometric　parameters　on　the　dimensionless　natural　frequencies　of　the　cantilever　plate.　The　amplitude-frequency　response　curves　and　the　basin　boundary　diagram　of　two　coexisting　steady-state　solutions　are　plotted　for　the　laminated　composite　piezoelectric　cantilever　plate.　The　nonlinear　dynamic　responses　of　the　laminated　composite　piezoelectric　cantilever　plate　under　combined　the　transverse　and　in-plane　excitations　are　investigated　by　changing　the　lay-up　parameters,　the　transverse　excitation,　the　voltage　excitation　and　the　in-plane　excitation.　The　periodic,　the　quasi-periodic,　the　chaotic　motions　and　the　nonlinear　stiffness　characteristics　can　be　found.　The　nonlinear　dynamic　behaviors　help　us　to　optimize　the　structural　and　physical　parameters　of　the　laminated　composite　piezoelectric　cantilever　plate　under　combined　the　transverse　and　in-plane　excitations.