In　order　to　meet　the　demand　of　temperature　deformation,　generally　only　one　fixed-pier　is　set　in　a　continuous　bridge.　As　a　result,　unfortunately,　all　the　longitudinal　seismic　loads　are　applied　to　one　fixed　pier,　which　may　result　in　the　damage　of　the　fixed　pier　and　the　expansion　joint,　and　even　lead　to　a　falling-off.　For　this　reason,　an　acceleration　activating　locking　dowel　is　developed.　The　device　is　designed　to　be　installed　between　the　piers　and　beams,　which　can　prohibit　the　relative　displacement　between　the　sliding　piers　and　the　bridge　once　the　earthquake　occurs　and　help　the　piers　to　collaboratively　bear　the　longitudinal　seismic　force,thus　reduce　the　seismic　response.　Meanwhile,　a　case　study　of　a　practical　project　is　conducted　to　illustrate　the　damping　effect　of　the　locking　dowel　and　its　influence　factors.　According　to　the　research　results,　the　locking　dowel　can　significantly　reduce　the　seismic　actions　on　the　fixed　pier　and　the　relatively　displacement　between　the　sliding　piers　and　the　bridge,　and　thus　improve　the　seismic　performance　of　a　continuous　bridge.　Besides,　the　damping　effect　of　the　device　is　mainly　determined　by　the　acceleration　activating　threshold　and　locking　clearance.　©　2016,　Engineering　Mechanics　Press.　All　right　reserved.