Based　on　Gushan　Bridge,　the　seismic　responses　of　structure　with　viscous　damper　is　studied.　The　influence　of　damping　coefficient　C　and　damping　exponent　ξ　on　the　displacements　and　internal　forces　of　key　sections　such　as　tower　bottom,　main　girder　and　so　on　is　discussed　by　the　non-linear　dynamic　time-history　analysis　method.　C　=　1500kN/(m　·　s)0,3,ξ　=0.　30　is　recommended　to　be　the　best　parameters　for　Gushan　Bridge.　The　analysis　shows　that　setting　dampers　with　recommended　parameters　in　longitudinal　direction　of　bridge　can　eliminate　the　displacements　and　internal　forces　of　key　sections　effectively.