Nonlinear　behaviors　of　thin-walled　Euler-Bernoulli　beams　with　varying　rotating　speed　which　are　attached　to　a　rigid　hub　are　investigated.　Centrifugal　force,　aerodynamic　load　and　the　perturbed　angular　speed　due　to　the　inconstant　air　velocity　are　considered.　The　nonlinear　factors　are　involved　in　displacement-strain　relationships.　The　nonlinear　governing　partial　differential　equations　of　high-speed　rotating　thin-walled　beam　are　established　by　using　Hamiltonian　Principle.　Then,　the　ordinary　differential　equations　of　the　rotating　thin-walled　beam　are　obtained　by　employing　Galekin＇s　approach　during　which　Galekin＇s　modes　satisfy　corresponding　boundary　conditions.　The　four-dimensional　nonlinear　averaged　equations　are　obtained　by　applying　the　method　of　multiple　scales.　In　this　paper,　the　case　of　1:1　internal　resonance　is　only　considered.　The　results　of　the　numerical　simulation　show　that　there　exits　complicated　nonlinear　behaviors　in　thin-walled　Euler-Bernoulli　beams　with　varying　rotating　speed.　©　2010　IEEE.