Based　on　the　three-dimensional　continuum　theory　of　viscous　damping　soil　and　the　radial　annular　complex　stiffness　transfer　model,　a　simplified　analytical　model　for　torsional　vibration　of　piles　in　viscoelastic　soil　is　established　by　considering　the　effects　of　both　radial　and　longtudinal　inhomogeinety　of　surrounding　soil.　The　solution　of　torsional　vibration　displacement　of　surrounding　soil　is　obtained　by　using　Laplace　transform　and　complex　stiffness　transfer　method,　then　the　form　is　coupled　into　the　dynamic　balance　equation　of　the　pile　by　using　the　complete　coupling　condition　of　pile-soil,　and　the　analytical　solution　of　torsion　impedance　of　pile　top　is　derived　by　the　method　of　torsional　impedance　transfer.　Furthermore,　the　obtained　analytical　solution　for　torsional　impedance　at　the　top　of　pile　is　degraded　and　compared　with　the　existing　solutions　to　verify　its　rationality.　Based　on　that,　an　extensive　parametric　analysis　is　also　conducted　to　discuss　the　influence　of　the　disturbance　degree,　disturbance　range　of　surrounding　soil,　necking　and　expanding　of　pile　on　the　torsional　impedance　at　the　top　of　pile,　which　can　provide　reference　and　guide　to　related　engineering　practice.　©　2021,　Editorial　Board　of　Journal　of　Vibration　Engineering.　All　right　reserved.