In　view　of　the　dynamic　interaction　between　the　foundation　and　the　structure,　the　influence　of　hard　interlayers　on　the　structural　seismic　response　of　a　nuclear　power　plant　was　analyzed　by　the　frequency-domain　analysis　method.　The　peak　acceleration　and　the　response　spectrum　of　the　seismic　response　of　the　nuclear　power　plant　on　the　soil　sites　with　different　types　of　hard　interlayers　were　calculated,　and　the　seismic　response　characteristics　of　the　structure　on　the　soil　site　with　hard　interlayers　were　explored.　The　results　show　that　the　peak　acceleration　and　acceleration　response　spectrum　of　the　seismic　response　of　the　nuclear　power　plant　structure　are　affected　by　the　thickness　of　the　hard　interlayers　in　the　site,　and　the　effect　is　not　negligible.　The　hard　interlayers　in　the　site　generally　reduces　the　horizontal　response　of　the　nuclear　power　plant　structure,　and　increases　the　vertical　response,　and　it　has　a　more　significant　impact　on　the　higher　frequency　band　spectrum　and　the　peak　acceleration　value,　but　when　the　thickness　of　the　hard　interlayers　is　large　enough,　the　effect　trend　has　the　opposite　result,　the　horizontal　direction　response　of　the　structure　is　increased　and　the　vertical　response　is　reduced.　The　influence　characteristic　of　the　hard　interlayers　in　the　site　on　the　structure　response　is　more　complex,　especially　the　spectral　characteristics　of　structure　response　will　be　changed.　The　influence　degree　is　closely　related　to　the　thickness　of　the　covering　soil,　the　thickness　of　the　hard　interlayers,　the　characteristics　of　the　input　ground　motion　and　the　structural　characteristics　of　the　nuclear　power　plant.　When　the　nuclear　power　plant　is　located　in　a　site　with　a　hard　interlayers,　special　attention　should　be　paid　to　its　adverse　effects　on　the　seismic　response　of　the　structure,　so　as　to　provide　reasonable　ground　motion　input　for　the　site　selection　of　actual　nuclear　power　projects　and　the　evaluation　of　structural　seismic　capacity.　©　2019,　The　Editorial　Board　of　Journal　of　Basic　Science　and　Engineering.　All　right　reserved.