The　influence　of　ultrasonic　surface　rolling　(USR)　treatment　on　microstructures,　residual　stress,　microhardness　and　fretting　wear　behaviors　of　20CrMoH　steel　under　different　quenching　temperatures　(740,　840　and　940　?)　was　systematically　investigated.　The　results　indicated　that　the　maximum　hardening　layer　depth　of　the　USR　treated　specimen　quenched　at　740　?　was　about　130　mu　m,　accompanied　by　grain　refinement　and　high-density　dislocations.　Simultaneously,　the　microhardness　was　mostly　increased　by　212　HV0.2　and　the　highest　surface　residual　compressive　stress　(RCS)　was　up　to-649　MPa.　The　fretting　wear　mechanisms　of　the　specimens　in　different　treatment　states　were　mainly　delamination　and　oxidative　wear.　The　volume　wear　loss　of　the　USR　treated　specimen　quenched　at　940　?　was　reduced　by　48%　compared　with　the　untreated　specimen　quenched　at　740　?.　This　could　be　benefited　from　the　protection　of　the　oxide　layer　and　the　effective　prevention　of　cracks　source　by　the　higher　surface　RCS,　as　well　as　the　grain　refinement　and　the　increase　in　dislocations　caused　by　USR　treatment.