This　paper　investigated　the　seismic　vulnerability　and　performance-based　assessment　of　offshore　monopile　wind　turbine　(OWT)　considering　turbine　blades.　A　three-dimensional　finite-element　model　of　NREL　5-MW　OWT　was　established　with　detailed　consideration　of　the　nonlinear-behavior　of　turbine,　monopile,　blades,　pile-soil　interactions　and　pile-water　interaction　etc.　Subsequently,　incremental　dynamic　analysis　and　fragility　evaluation　were　conducted　via　a　great　number　of　nonlinear　time　history　analysis　involving　far-field　and　near-fault　records　with　and　without　pulse　characteristics.　It　is　found　that　the　ignorance　of　turbine　blades　in　conventional　lumped　mass　(LM)　model　would　significantly　underestimate　the　vulnerability　of　OWT＇s　acceleration　responses,　and　more　importantly,　underestimates　the　stress　level　at　turbine　top,　misleading　the　failure　pattern　of　OWT　which　may　be　probably　damaged　at　both　top　and　middle　part　of　OWT　rather　than　solely　the　middle　part　as　estimated　by　the　LM　model　ignoring　the　effect　of　turbine　blades.　Finally,　it　can　be　concluded　that　the　modeling　of　turbine　blades　should　be　consider　in　the　numerical　studies.