Pre-stressed　high-strength　concrete　(PHC)　pipe　piles　have　been　widely　used　in　the　pile　foundations　of　buildings　and　bridges　which　are　usually　designed　elastic　based　on　the　capacity　design　principle.　However,　when　the　PHC　pipe　pile　comes　to　the　foundations　of　Integral　Abutment　Jointless　Bridges　(IAJBs),　limited　ductility　might　apply　in　order　to　accommodate　the　relatively　large　deformation　demand　under　the　effect　of　temperature　fluctuations　or　earthquake.　The　conventional　design　methods　for　PHC　pipe　piles　remain　in　doubt.　This　paper　focuses　on　low　cycle　pseudo-static　tests　on　4　PHC　pipe-pile　models　with　various　pre-stress　levels　to　gain　insight　into　their　mechanical　behaviors　with　consideration　of　soil-pile　interaction.　Medium　sand　was　employed　in　the　tests.　The　details　of　the　experiments　are　introduced,　including　design　of　the　models,　instrumentation　and　loading　scheme.　The　testing　results　indicate　that　the　damages　of　the　PHC　pipe　piles　are　mainly　concentrated　at　4D　to　8D　of　embedded　depths.　Moreover,　the　pre-stress　level　and　reinforcement　ratio　have　a　significant　influence　on　the　failure　mode　of　PHC　pipe　piles,　especially　on　the　distribution　of　internal　force　and　moment　along　piles.　It　is　found　that　the　interaction　effect　of　pile-soil　strengthens　with　the　pre-stress　level　which　is　beneficial　to　the　seismic　performance.　Furthermore,　the　backbone　of　the　PHC　pipe　piles　model　has　four　stages:　elastic,　elastic-plastic,　plastic　hardening,　and　failure.　It　is　concluded　that　PHC　pipe　piles　perform　favorably　plastic　and　ductile　behavior,　and　their　failure　modes　are　flexural　(bending)　not　brittle　(shear).　Finally,　the　PHC　pipe　pile　has　an　appreciable　energy　dissipation　and　deformation　capacity,　and　hence　can　be　used　for　pile　foundations　in　IAJBs.