To　investigate　the　seismic　performance　and　isolation　effect　of　a　high-temperature　gas-cooled　reactor,　a　1/20　scale　model　including　a　reactor,　a　spent-fuel　plant,　and　a　nuclear　auxiliary　plant　was　fabricated.　In　addition,　220　mm　lead-rubber　bearings　were　designed　and　produced　for　use　in　the　shaking　table　test,　which　included　both　isolated　and　nonisolated　conditions.　Two　historical　earthquake　records　and　three　artificial　earthquake　motions　were　used　to　input　the　ground　motion　in　the　tests.　The　results　demonstrated　that　the　seismic　performance　of　the　plant　was　better　and　that　the　structure　was　in　an　elastic　state,　under　a　safe　shutdown　earthquake　event.　Isolation　bearings　were　found　to　effectively　reduce　the　dominate　frequency　of　the　structure.　The　acceleration　amplification　factor　of　the　superstructure　was　found　to　be　less　than　1.　The　isolation　test　results　showed　that　the　peak　of　the　floor　response　spectrum　at　the　pressure　vessel　support　was　less　than　0.1　g.　In　the　nonisolation　test,　the　peak　of　the　floor　response　spectrum　was　greater　than　1　g.　In　the　isolation　test,　the　relative　displacement　of　the　structure　was　less　than　1.1　mm,　which　was　relatively　small.　The　structure　maintained　a　good　isolation　performance　and　exhibited　improved　safety　under　extreme　ground　motion.