The　longitudinal　fluctuating　forces　of　a　propeller　are　a　major　cause　of　sound　radiation　of　an　underwater　vehicle　in　the　low　frequency　range.　A　hydraulic　leveraged　dynamic　anti-resonance　vibration　isolator　(HLVI)　is　proposed　to　attenuate　the　longitudinal　vibration　of　a　shaft　system　transmitted　to　the　hull.　The　semi-analytical　model　of　the　shafting　system　with　and　without　the　isolator　is　set　up　by　employing　the　frequency　response　synthesis　method,　in　which　the　elasticity　of　the　foundation　is　taken　into　consideration.　Compared　to　the　traditional　isolation　scheme　and　DVA,　the　proposed　control　scheme　will　not　change　the　longitudinal　effective　stiffness　and　needs　a　small　mass　to　attenuate　the　longitudinal　vibration　of　the　shafting　system.　A　parametric　study　was　conducted　to　investigate　the　key　parameters　of　the　isolator　and　their　impact　on　its　isolation　performance.　An　experimental　apparatus　is　set　up　to　validate　the　isolation　scheme.　The　acceleration　frequency　response　results　of　the　shafting　system　under　axial　excitation　with　both　the　frequency　sweep　method　and　discrete　sinusoidal　frequencies　are　presented　and　discussed.　The　results　indicate　that　the　proposed　method　is　capable　of　attenuating　the　corresponding　longitudinal　vibration　of　the　shafting　system.