The　nonlinear　resonant　responses,　mode　interactions,　and　multitime　periodic　and　chaotic　oscillations　of　the　cantilevered　pipe　conveying　pulsating　fluid　are　studied　under　the　harmonic　external　force　in　this　research.　According　to　the　nonlinear　dynamic　model　of　the　cantilevered　beam　derived　using　Hamilton＇s　principle　under　the　uniformly　distributed　external　harmonic　excitation,　we　combine　Galerkin　technique　and　the　method　of　multiple　scales　together　to　obtain　the　average　equation　of　the　cantilevered　pipe　conveying　pulsating　fluid　under　1　:　3　internal　resonance　and　principal　parametric　resonance.　Based　on　the　average　equation　in　the　polar　form,　several　amplitude-frequency　response　curves　are　obtained　corresponding　to　the　certain　parameters.　It　is　found　that　there　exist　the　hardening-spring　type　behaviors　and　jumping　phenomena　in　the　cantilevered　pipe　conveying　pulsating　fluid.　The　nonlinear　oscillations　of　the　cantilevered　pipe　conveying　pulsating　fluid　can　be　excited　more　easily　with　the　increase　of　the　flow　velocity,　external　excitation,　and　coupling　degree　of　two　order　modes.　Numerical　simulations　are　performed　to　study　the　chaos　of　the　cantilevered　pipe　conveying　pulsating　fluid　with　the　external　harmonic　excitation.　The　simulation　results　exhibit　the　existence　of　the　period,　multiperiod,　and　chaotic　responses　with　the　variations　of　the　fluid　velocity　or　excitation.　It　is　found　that,　in　the　cantilevered　pipe　conveying　pulsating　fluid,　there　are　the　multitime　nonlinear　vibrations　around　the　left-mode　and　the　right-mode　positions,　respectively.　We　also　observe　that　there　exist　alternately　the　periodic　and　chaotic　vibrations　of　the　cantilevered　pipe　conveying　pulsating　fluid　in　the　certain　range.