A　flexural　pile　foundation　in　integral　abutment　jointless　bridges　(IAJBs)　is　usually　used　in　practical　engineering　to　absorb　the　horizontal　reciprocating　deformations　induced　by　the　effects　of　ambient　temperature　or　earthquakes.　Therefore,　a　pseudo-static　test　on　different　types　of　piles　in　IAJBs　was　carried　out　to　study　their　seismic　performance　and　deformation　capability　under　low-cycle　horizontal　reciprocating　displacement　loads.　The　behaviors　of　piles,　in　terms　of　damage　modes,　horizontal　deformations　and　bearing　capacities,　and　distributions　of　strain　and　bending　moment,　were　compared.　The　test　results　indicate　that　with　an　increase　in　the　reinforcement　ratio　and　pre-stressed　level,　the　pile　damage　position　develops　downward　to　a　larger　embedded　depth.　The　effect　of　soil-pile　interaction　and　crack　resistance　can　be　enhanced　by　increasing　the　reinforcement　ratio　and　pre-stressed　level.　Moreover,　a　rectangular　pile　has　better　pile-soil　interaction　and　energy　dissipation　capacity　than　a　circular　pile.　The　inflection　points　of　pile　deformation　will　be　deeper　with　increases　in　the　reinforcement　ratio　and　section　size,　which　can　increase　the　effective　length　and　horizontal　deformation　capacity　of　the　pile.　Compared　with　the　circular　pile,　the　steel　H-pile　has　a　better　elastic-plastic　deformation　capacity,　ductility　and　energy　dissipation　capacity.　The　bearing　ratio　is　a　suitable　indicator　to　evaluate　the　effect　of　pile-soil　interaction.　The　test　results　also　indicate　that　the　skeleton　curves　of　the　concrete　pile　are　expressed　using　displacement　characteristic　points　of　elastic　ultimate　displacement,　unobservable　cracking　displacement,　observable　cracking　displacement,　crushing　displacement,　peak　displacement　and　limiting　displacement.　The　displacement　characteristic　point　improves　with　the　increase　in　the　reinforcement　ratio　and　pre-stressed　level.　Based　on　the　skeleton　curves　of　the　concrete　pile,　a　displacement-based　seismic　design　criterion　＇three-stage　seismic　fortification　levels　and　five-grade　damage　levels＇　in　IAJBs　is　proposed,　which　can　provide　a　reference　for　the　design　and　formulation　of　existing　specifications.　©　2021,　Editorial　Department　of　China　Journal　of　Highway　and　Transport.　All　right　reserved.