The　increasing　number　of　wind　turbines　in　areas　of　active　seismicity　has　attracted　scientific　interest　to　evaluate　the　seismic　responses　of　offshore　wind　turbine　(OWT).　The　pile-soil　dynamic　interaction　can　have　significant　influence　on　the　seismic　responses　of　OWT.　This　research　aims　at　investigating　the　seismic　responses　of　a　5　MW　OWT　considering　nonlinear　pile-soil　dynamic　interaction.　The　pile　is　assumed　to　be　rest　on　the　rigid　bedrock.　The　soil　nonlinearity　is　accounted　for　approximately　using　an　inhomogeneous　boundary　zone　around　the　pile　and　a　homogeneous　zone　outside　the　boundary　zone.　For　simplification　purpose,　the　dynamic　analysis　of　the　OWT　is　divided　into　two　stages.　In　the　first　stage,　the　dynamic　resistance　factor　of　soil　layer　with　radially　inhomogeneous　boundary　zone　is　obtained　by　using　transfer　matrix　method.　In　the　second　stage,　a　substructure　model　for　dynamic　responses　of　OWT　including　structure-pile-soil　interaction　is　proposed.　A　three-dimensional　(3D)　finite　element　model　(FEM)　in　Abaqus　is　used　to　verify　the　proposed　method.　Numerical　results　show　that　the　proposed　model　agrees　well　with　the　3D　FEM.　Finally,　the　effects　of　pile-soil　interaction　on　the　seismic　responses　of　a　5　MW　OWT　are　investigated.　©　2021　Elsevier　Ltd