To　study　the　effects　of　different　site　ground　motions　on　curved　bridges,　a　scale　model　of　a　curved　bridge　with　the　scale　ratio　of　1:10　was　designed　by　taking　a　curved　bridge　with　5%　longitudinal　slopes　as　the　research　object.　Ground　motions　in　different　site　conditions　were　selected　for　shaking　table　test.　The　results　show　that　the　influence　of　site　conditions　on　the　response　of　the　curved　bridge　was　significant.　The　structural　response　increased　gradually　with　the　site　classification　changing　from　I　to　IV.　Compared　to　unidirectional　input,　the　structural　response　under　bidirectional　input　was　obviously　large.　The　structural　response　of　the　main　girder　was　affected　the　directions　of　the　excitation.　When　the　bridge　was　excited　by　the　ground　motion　in　the　longitudinal　direction,　the　main　girder　moved　horizontally　androtated　along　the　fixed　pier　simultaneously.　When　the　bridge　was　excited　by　the　ground　motion　in　the　transverse　direction,　the　movement　of　main　girder　was　mainly　translational.　The　structural　response　of　the　curved　bridge　was　related　to　the　bridge　arrangement　and　the　direction　of　the　principal　seismic.　When　the　curved　bridge　was　parallel　to　the　direction　of　the　principal　seismic,　the　tangential　displacement　response　was　remarkable.　The　radial　displacement　was　more　significant　when　it　was　perpendicular　to　the　direction　of　the　principal　seismic.　The　smaller　the　angle　between　the　displacement　direction　of　the　pier　and　the　direction　of　the　ground　motion　excitation　was,　the　greater　the　displacement　response　of　the　pier　became.　The　higher　the　pier　height　was,　the　more　obvious　the　magnification　of　the　displacement　of　the　pier　was,　and　the　more　sensitive　the　tangential　displacement　of　the　fixed　pier　was　to　the　seismic　response.　When　the　curved　bridge　was　parallel　to　the　direction　of　the　principal　seismic　in　unidirectional　input,　the　bearing　of　the　low　pier　was　easy　to　fall　off.　When　bidirectional　input　and　the　curved　bridge　were　perpendicular　to　the　direction　of　the　principal　seismic,　the　high　pier　was　easy　to　fall　off.　Therefore,　much　attention　should　be　paid　to　the　seismic　design　and　analysis　of　curved　bridges.　©　2019,　Editorial　Board　of　Journal　of　Harbin　Institute　of　Technology.　All　right　reserved.