This　paper　investigates　the　complicated　dynamics　behavior　and　the　evolution　law　of　the　nonlinear　vibrations　of　the　simply　supported　laminated　composite　piezoelectric　beam　subjected　to　the　axial　load　and　the　transverse　load.　Using　the　third-order　shear　deformation　theory　and　the　Hamilton＇s　principle,　the　nonlinear　governing　equations　of　motion　for　the　laminated　composite　piezoelectric　beam　are　derived.　Applying　the　method　of　multiple　scales　and　Galerkin＇s　approach　to　the　partial　differential　governing　equation,　the　four-dimensional　averaged　equation　is　obtained　for　the　case　of　principal　parametric　resonance　and　1:　9　internal　resonance.　From　the　averaged　equations　obtained,　numerical　simulation　is　performed　to　study　nonlinear　vibrations　of　the　laminated　composite　piezoelectric　beam.　The　axial　load,　the　transverse　load,　and　the　piezoelectric　parameter　are　selected　as　the　controlling　parameters　to　analyze　the　law　of　complicated　nonlinear　dynamics　of　the　laminated　composite　piezoelectric　beam.　Based　on　the　results　of　numerical　simulation,　it　is　found　that　there　exists　the　complex　nonlinear　phenomenon　in　motions　of　the　laminated　composite　piezoelectric　beam.　In　summary,　numerical　studies　suggest　that　periodic　motions　and　chaotic　motions　exist　in　nonlinear　vibrations　of　the　laminated　composite　piezoelectric　beam.　In　addition,　it　is　observed　that　the　axial　load,　the　transverse　load　and　the　piezoelectric　parameter　have　significant　influence　on　the　nonlinear　dynamical　behavior　of　the　beam.　We　can　control　the　response　of　the　system　from　chaotic　motions　to　periodic　motions　by　changing　these　parameters.