The　dynamic　responses　of　saturated　soil　are　the　always　concerning　problems　of　soil　dynamics.　The　liquefaction　caused　by　cyclic　loadings　often　increases　the　pore　pressure　and　decreases　the　strength　of　the　soil.　In　addition,　for　the　site　with　large　size　saturated　soil,　large　numbers　of　degrees　of　freedom　often　lead　to　low　calculation　efficiency,　and　restrict　the　development　of　the　numerical　method　of　saturated　soil.　Therefore,　the　proposed　fully　explicit　finite　element　method　for　the　equations　of　saturated　porous　medium　in　u-p　formulation　is　implemented　into　the　OpenSees　software.　By　using　the　element　and　constitutive　models　in　OpenSees,　the　efficient　and　explicit　computation　of　the　dynamic　responses　of　saturated　soils　can　be　realized　in　this　paper.　In　a　two-dimensional　saturated　model,　the　elastic　dynamic　responses　obtained　from　the　Newmark　method　are　compared　with　the　results　obtained　from　the　embedded　method.　Two　results　are　in　good　agreement,　which　verify　the　embedded　algorithm.　The　proposed　algorithm　is　used　to　compute　the　nonlinear　free　field　seismic　responses　of　the　seabed　soil.　This　method　simulates　liquefaction　process,　failure　modes　and　the　lateral　deformation　of　the　seabed　soil　effectively.　The　proposed　algorithm　illustrates　significant　advantages　in　terms　of　computational　efficiency.　©　2018,　Science　Press.　All　right　reserved.