In　order　to　investigate　the　effect　of　soil-structure　interaction　(SSI)　on　the　earthquake　characteristics,　and　the　foundation　pier　effect　of　the　soil　surrounding　on　peak　response　of　the　continuous　girder　seismically　isolated　bridge　with　lead　rubber　bearings　(LRB)　under　bi-directional　earthquake　excitation.　An　analytical　method　of　earthquake-response　is　carried　out　in　time　domain　using　complex　modal　analysis,　and　the　peak　responses　of　a　three-span　continuous　girder　seismically　isolated　bridge　are　compared　with　consideration　or　ignorance　of　SSI　effect.　A　parametric　study　is　also　conducted　to　investigate　the　effect　of　bearing　parameters　on　the　response　of　isolated　bridge　system.　It　has　important　effects　of　SSI　on　the　earthquake　response　of　continuous　girder　seismically　isolated　bridges.