With　the　development　of　modern　industrial　equipment　and　the　requirement　in　energy　conservation　and　emission　reduction,　the　traditional　high　carbon　and　high　chromium　steel　which　is　widely　used　as　bearing　material　cannot　meet　these　demands.　Therefore,　it　is　of　paramount　importance　to　exploit　novel　materials　used　as　bearings　with　long　life.　In　recent　years,　some　new　techniques　have　been　used　to　improve　the　bearing　life,　such　as　physical　vapor　deposition　(PVD),　chemical　vapor　deposition　(CVD)　and　plasma　immersion　implantation　and　so　on.　All　these　techniques　are　attempting　to　increase　the　surface　hardness　of　the　bearing.　Though　the　bearing　life　has　been　extended　to　some　extent,　the　application　range　of　these　techniques　is　limited　by　the　price　factor　and　the　dimensions　of　components.　Ultrahigh-carbon　steels　(UHCSs)　have　been　studied　for　many　years,　and　they　possess　outstanding　mechanical　properties　and　wear　resistance.　Therefore,　it　is　interesting　to　explore　the　probability　whether　UHCSs　can　be　used　in　the　bearing　application.　It　is　well　known　that　if　bearings　are　well　assembled,　lubricated　and　loaded,　rolling　contact　fatigue　(RCF)　is　the　main　failure　form.　Accordingly,　the　evaluation　of　the　resistance　to　RCF　is　of　paramount　importance　for　bearing　materials.　The　RCF　properties　of　UHCSs　have　never　been　studied　in　the　past　decades.　Therefore,　in　this　work,　the　RCF　behavior　of　a　UHCS　with　1.29%C　(mass　fraction)　was　investigated　in　well　lubricated　conditions,　using　a　flat　washer-type　RCF　tester.　In　order　to　shorten　the　testing　time,　the　maximum　Hertzian　stress　was　set　as　4400　MPa.　For　comparison,　the　RCF　lives　of　conventional　GCr15　and　SKF3　bearing　steels　were　also　tested　under　the　same　conditions.　The　results　showed　that　the　rated　life　L-10　of　the　UHCS　was　2.14　and　1.81　times　longer　than　those　of　the　GCr15　and　SKF3　steels,　respectively.　Since　more　spherical　residual　carbide　particles　could　be　used　to　retard　the　grain　growth　during　austenitization　for　the　UHCS,　the　prior　austenite　grain　size　of　the　UHCS　was　only　6.91　mu　m.　However,　the　prior　austenite　grain　sizes　of　the　GCr15　and　SKF3　steels　were　13.52　and　11.41　mu　m,　respectively.　Therefore,　the　average　size　of　martensite　plate　of　the　UHCS　was　approximately　half　of　those　of　the　GCr15　and　SKF3　steels.　Finer　grains　were　expected　to　retard　the　crack　initiation　and　propagation,　and　then　the　RCF　life　would　be　prolonged.　On　the　other　hand,　the　carbon　content　and　the　volume　fractions　of　precipitates　in　the　martensite　plates　of　the　quenched　and　tempered　UHCS　were　both　higher　than　those　of　the　GCr15　and　SKF3　steels.　These　factors　made　the　UHCS　harder　than　GCr15　and　SKF3　steels,　which　was　beneficial　for　the　improvement　of　RCF　life.