Using　a　hollow-cylinder　torsional　shear　apparatus,　we　experimentally　investigated　the　development　characteristics　of　excess　pore　water　pressure　(EPWP)　in　saturated　marine　coral　sand.　These　coral　sand　specimens　were　tested　under　various　values　of　nonplastic　fines　content　(FC),　relative　density　(Dr),　and　cyclic　stress　ratio　(CSR).　A　laboratory　cyclic　torsional　shear　test　under　isotropic　consolidation　showed　that　the　development　rate　of　the　EPWP　ratio　(Ru)　versus　the　number　of　cycles　(N)　increased　with　increasing　FC　and　CSR　but　decreased　with　increasing　Dr.　Additionally,　the　increase　in　FC　significantly　reduced　the　cyclic　resistance　ratio　(CRR)　of　marine　coral　sand.　For　a　given　Dr　and　FC,　Ru　of　the　specimens　under　different　CSR　was　uniquely　related　to　the　amplitude　of　the　shear　strain　(γa).　Moreover,　a　pore　pressure　evaluation　model　based　on　shear　strain　characteristics　was　established.　The　measurements　showed　that　the　EPWP　model　parameter　A　is　a　soil-specific　constant,　and　the　density-corrected　EPWP　model　parameter　B/(Dr)1.5　has　a　single　negative-power　relationship　with　the　equivalent　skeleton　void　ratio　(esk*.　©　2023