In　this　paper,　the　bifurcations　and　chaos　dynamics　of　a　hyperjerk　system　with　antimonotonicity　are　investigated　via　the　analytical　methods　and　numerical　calculations.　We　discuss　the　local　stabilities　of　equilibrium　points　and　its　bifurcations　depending　on　parameters.　The　predicted　bifurcations　of　periodic　orbits　including　flip　bifurcation,　fold　bifurcation　and　symmetry-breaking　bifurcation　are　investigated.　The　accurate　relations　between　parameters　are　established　to　identify　the　type　of　bifurcation　appearing　in　system　efficiently.　Such　simple　system　has　very　abundant　dynamical　behaviors,　including　period-doubling　cascades　route　to　chaos,　intermittency　regime,　antimonotonicity　and　boundary　crisis.　The　coexisting　dynamics　is　confirmed　effectively　by　using　basins　of　attraction,　bifurcation　diagram,　Lyapunov　exponent　spectrum　and　phase　portraits.　The　research　reveals　the　richness　and　complexity　of　potential　stable　states　to　which　this　chaotic　hyperjerk　system　can　evolve　and　offers　flexibility　in　realization　of　various　applications　including　secure　communications.