The　flexural　pile　foundation　is　used　in　integral　abutment　jointless　bridges　(IAJBs)　in　practical　engineering　to　effectively　dissipate　the　horizontal　reciprocating　deformation　induced　by　the　ambient　temperature　or　earthquake　loadings.　Various　types　of　flexural　piles　including　the　H-shaped　steel　pile　(HP),　prestressed　concrete　pile　(PC),　prestressed　high-strength　concrete　pile　(PHC)　as　well　as　the　reinforcement　concrete　pile　(RC)　have　been　implemented　in　IAJBs.　However,　there　is　a　lack　of　comprehensive　studies　on　the　flexural　deformation　and　seismic　performances　of　these　piles.　In　order　to　investigate　and　compare　their　mechanical　behaviors　and　seismic　performances,　a　low-cycle　pseudo-static　test　on　several　different　types　of　piles　was　carried　out.　The　test　results　indicated　that　the　plastic　hinge　location　of　piles　moved　to　a　deeper　pile　depth　with　the　increase　of　reinforcement　ratio,　buried　pile　depth　and　prestressing　level,　which　led　to　better　pile-soil　interaction.　The　crack　resistance　of　a　concrete　pile　was　improved　as　the　reinforcement　ratio　and　prestressing　level　increased.　Moreover,　the　rectangular　pile　had　a　better　soil-pile　interaction　and　energy　dissipation　capacity　than　the　circular　pile.　The　inflection　point　of　the　pile　deformation　shifted　deeper　as　reinforcement　ratio,　buried　pile　depth　and　prestressing　level　increased,　which　improved　the　effective　length　and　horizontal　deformation　capacity　of　piles.　The　H-shaped　steel　pile　showed　a　better　elastic-plastic　deformation　capacity,　ductility　and　energy　dissipation　capacity　as　compared　to　the　concrete　pile.　Moreover,　the　pile　having　a　higher　bearing　ratio　sustained　larger　lateral　loads　whereas　the　surrounding　soil　was　subjected　to　higher　loads.　Finally,　new　seismic　design　criteria　of　three-stage　seismic　fortification　and　five　damage　level　for　the　concrete　piles　of　IAJBs　were　proposed.