To　analyze　the　tensile　performance　of　seismic　isolated　rubber　bearings,　a　two-spring　model　is　established　for　calculating　the　tensile　stiffness　of　bearings.　According　to　the　shear　and　tensile　geometric　deformation　condition　of　the　bearings,　the　theoretical　formula　of　tensile　stiffness　are　derived　for　rubber　bearings　subjected　to　shear　and　tensile　loads.　Based　on　the　derived　expressions,　the　relationship　between　tensile　stiffness　and　shear　deformationis　is　analyzed.　Furthermore,　the　analytical　results　are　compared　with　the　finite　element　analysis　results　and　the　tensile　experimental　results.　The　results　show　that　the　tensile　stiffness　expressions　derived　in　this　paper　can　be　used　to　simulate　the　tensile　stiffness　variations　for　rubber　seismic　isolated　bearings　with　shear　deformation　less　than　100%.