Shaking-Table　testing　of　seismic　performance　and　dynamic　interaction　of　prestressed　highstrength　concrete　(PHC)　pipe-piles　in　saturated　soils　and　unsaturated　soils　was　conducted　using　a　series　of　sine　waves,　typical　earthquake　waves,　as　well　as　artificial　ground　motions　based　on　in　situ　measurements.　The　presented　test　results,　involving　the　time　history　of　water　pore　pressure　ratio　and　the　responding　displacement　related　to　soil　liquefaction,　indicated　that　the　natural　frequency　of　soil-pile　system　decreased　because　of　gradual　degradation　of　soil　and　pile　shift.　Moreover,　the　peak　displacement　responses　of　piles　in　saturated　soil　were　larger　than　the　peak　displacements　in　unsaturated　soil.　In　addition,　prestressing　in　pile　was　beneficial　to　the　resistance　of　pile　damage　or　degradation.　These　experimental　results　were　able　to　calibrate　FE　models　and　to　provide　a　database　for　seismic　design　of　PHC　pipe-piles.　Copyright　©　2016　by　ASTM　International,　100　Barr　Harbor　Drive,　PO　Box　C700,　West　Conshohocken,　PA　19428-2959.