According　to　the　experience　of　vibratory　compaction,　a　nonlinear　soil　dynamic　model　was　established.　This　model　was　used　to　elucidate　the　dynamic　characteristics　of　different　soil　compacted　processes　including　elastic-plastic　nonlinearity　and　jump　vibration.　Based　on　the　first-order　approximation,　the　asymmetrical　nonlinear　hysteretic　restoring　force　was　expressed　by　equivalent　damping　and　equivalent　stiffness　through　the　harmonic　linearization　method.　The　dynamic　response　of　the　two-DOF　vibrating　compaction　system　was　derived　by　using　the　optimization　method.　By　means　of　numerical　simulation,　the　dynamic　evolution　of　vibratory　roller-soil　system　was　studied.　During　the　beginning　of　vibratory　compaction,　soil　is　in　the　elastic-plastic　range,　and　roller　keeps　coupling　with　soil.　At　the　ending　of　vibratory　compaction,　density　of　soil　increases,　sub-harmonics　may　occur　while　roller　takes　a　jump　vibration,　and　chaos　could　be　induced　by　some　special　conditions.　Adjustment　of　excitation　amplitude　and　excitation　frequency　could　availably　control　the　jump　vibration　of　roller　and　avoid　the　chaos　response.