For　the　Rotor-nacelle　assembly　(RNA),　which　is　also　known　as　the　head　of　wind　turbine　(WT),　the　frequently　used　simplified　models　mainly　include　point　mass　(RNA_M),　point　mass　with　eccentricity　(RNA_ME),　point　mass　with　eccentricity　and　rotational　inertia　(RNA_MEJ)　and　rigid　nacelle　with　rigid　blades　(RNA_RB).　Based　on　the　prototype　of　the　NREL　5MW　offshore　wind　turbine　(OWT)　with　monopile　foundation,　Abaqus　is　adopted　to　establish　WT　models　with　these　four　simplified　RNA　models.　Taking　the　elaborated　RNA_FB　WT　model　as　the　baseline,　this　paper　analyzes　the　influences　of　these　different　simplified　RNA　models　on　the　natural　frequency　and　seismic　response　of　the　WT　structure.　The　results　show　that　for　the　problems　involving　only　the　1st　order　mode　of　the　supporting　structure,　the　calculated　frequency　values　of　the　four　simplified　RNA　models　are　all　accurate　and　reliable;　The　RNA_MEJ,　RNA_RB　or　RNA_FB　model　should　be　used　when　the　2nd　order　mode　or/and　torsion　mode　of　the　supporting　structure　is　involved;　The　RNA_FB　model　should　be　used　when　higher-order　modes　of　the　supporting　structure　are　involved.　For　the　seismic　response　analysis　of　WT　structure,　the　structural　responses　calculated　by　the　RNA_MEJ　and　RNA_RB　models　are　more　accurate,　but　the　maximum　relative　deviation　(RD)　of　the　majority　of　their　structural　response　peaks　still　exceeds　10%.　Therefore,　the　simplified　RNA　models　should　be　used　cautiously　in　engineering　application.　©　2023　Tsinghua　University.　All　rights　reserved.