With　the　rapid　development　of　rail　transit,　the　wear　problem　of　track　has　become　a　serious　challenge.　Laser　quenching　is　a　new　surface　modification　process,　and　it　is　expected　to　improve　the　service　life　of　the　track.　Laser　quenching　was　carried　on　the　surface　of　rails　by　using　6　kW　fiber　laser.　The　microstructure,　hardness,　wear　resistance,　and　contact　fatigue　resistance　(CFR)　of　the　phase　transformation　hardening　layer　were　studied　by　optical　microscope　(OM),　scanning　electron　microscopy　(SEM),　X-ray　diffraction　(XRD),　microhardness　tester,　and　wear　tester.　The　results　show　that　the　microstructure　of　the　hardened　layer　is　composed　of　fine　martensite　and　a　small　fraction　of　retained　austenite.　The　microstructure　of　substrate　is　pearlite　and　ferrite.　The　hardness　of　rails　quenched　by　the　laser　increased　nearly　two　times　than　that　of　the　un-treated　track　materials.　When　the　laser　power　is　1000　W,　the　depth　of　hardened　layer　reaches　0.8　mm,　and　the　wear　resistance　of　hardened　layer　increases　167%　than　that　of　the　substrate.　The　number,　length,　and　depth　of　fatigue　cracks　decreased　on　the　cross-section　of　worn　rails　after　laser　quenching,　which　indicates　that　laser　quenching　can　improve　the　CFR　of　rails.