A　cooling　water　tank　is　an　important　component　of　a　passive　containment　cooling　system　(PCS)　of　an　advanced　nuclear　power　plant.　Large-amplitude　sloshing　occurs　easily　under　long-period　earthquakes　because　of　the　low　sloshing　frequency　of　liquid.　Therefore,　the　dynamics　of　a　cooling　water　tank　must　be　considered　when　the　nuclear　power　plant　is　analyzed.　The　hydrodynamic　pressure　and　attenuation　data　of　wave　height　in　shaking　table　test　are　measured　and　used　to　calculate　the　sloshing　frequencies　and　damping　ratio　of　liquid.　Moreover,　test　results　are　compared　with　those　from　numerical　analysis　and　theoretical　calculation　of　equivalent　model..This　study　demonstrated　that　the　numerical　analysis　and　equivalent　model　could　properly　simulate　the　test　results　and　analyze　the　sloshing　dynamics　of　the　liquid　in　a　PCS　water　tank.　It　is　proved　that　the　proposed　measuring　method　is　accurate　and　the　proposed　equivalent　model　is　reasonable.　©　2018,　Editorial　Department　of　Journal　of　HEU.　All　right　reserved.