In　order　to　study　the　hysteretic　behavior　of　the　ultra-high　strength　steel　(UHSS),　cyclic　tests　on　Q1100　UHSS　with　nominal　yield　strength　equal　to　1100　MPa　are　conducted　in　the　present　study.　The　strength　softening,　preserved　strength,　and　energy　dissipation　capacity　of　Q1100　UHSS　are　analyzed.　The　influences　of　the　loading　scheme　and　initial　residual　strain　on　the　hysteretic　behavior　of　UHSS　are　investigated.　It　is　found　that　Q1100　UHSS　shows　a　significant　softening　behavior　under　cyclic　loading.　The　strength　decrease　is　relatively　rapid　at　the　beginning　of　the　cyclic　loading　and　then　tends　to　stabilize.　The　decrease　of　the　strength　of　UHSS　with　larger　residual　strain　tends　to　be　more　slowly.　The　energy　dissipation　coefficient　of　Q1100　UHSS　increases　with　the　increase　of　strain　amplitude.　The　sampling　direction　has　a　negligible　effect　on　the　hysteretic　behavior　of　Q1100　UHSS.　A　nonlinear　combined　hardening　constitutive　model　is　calibrated　for　various　cyclic　loading　schemes　by　using　an　automatic　calibration　method　and　the　cyclic　behavior　of　Q1100　UHSS　is　predicted　well.