The　American　standards　about　seismic　analysis　of　safety-related　nuclear　structure　were　investigated,　and　the　seismic　input　interface　location　of　for　non-rock　site　and　the　methods　of　determining　input　seismic　motion　were　discussed,　and　then　the　effect　of　the　soil　layer　thickness　between　structure　foundation　and　base　rock　on　seismic　response　of　nuclear　structure　was　analyzed　by　the　professor　software　EERA　and　ACS　SASSI.　The　results　show　that,　at　the　relative　high　frequency　components　of　the　structural　seismic　response　on　the　soil　site　are　higher　than　those　on　rock　site　in　the　case　of　shallow　overlay　soil,　and　only　in　the　case　of　sufficiently　deep　overlay　soil,　the　reduction　of　relative　high　frequency　components　of　the　structural　seismic　response　exists.Furthermore,　the　foundation　treatment　scheme　of　replacing　soil　with　plain　concrete　was　analyzed,　and　the　comparison　of　structural　seismic　responses　for　the　cases　of　the　foundation　treatment　scheme　and　the　hard　rock　foundation　shows　a　reasonable　good　agreement,　and　also　a　numerical　model　of　structure　with　the　foundation　of　replacing　soil　with　plain　concrete　was　proposed.　©　2021,　The　Editorial　Board　of　Journal　of　Basic　Science　and　Engineering.　All　right　reserved.