This　paper　investigates　the　hydrodynamic　characteristics　of　floating　truncated　cylinders　undergoing　horizontal　and　vertical　motions　due　to　earthquake　excitations　in　the　finite　water　depth.　The　governing　equation　of　the　hydrodynamic　pressure　acting　on　the　cylinder　is　derived　based　on　the　radiation　theory　with　the　inviscid　and　incompressible　assumptions.　The　governing　equation　is　solved　by　using　the　method　of　separating　variables　and　analytical　solutions　are　obtained　by　assigning　reasonable　boundary　conditions.　The　analytical　result　is　validated　by　a　numerical　model　using　the　exact　artificial　boundary　simulation　of　the　infinite　water.　The　main　variation　and　distribution　characteristics　of　the　hydrodynamic　pressure　acting　on　the　side　and　bottom　of　the　cylinder　are　analyzed　for　different　combinations　of　wide-height　and　immersion　ratios.　The　added　mass　coefficient　of　the　cylinder　is　calculated　by　integrating　the　hydrodynamic　pressure　and　simplified　formulas　are　proposed　for　engineering　applications.　The　calculation　results　show　that　the　simplified　formulas　are　in　good　agreement　with　the　analytical　solutions.