Compared　with　middle-span　bridges,　seismic　response　of　long-span　bridges　is　more　complicated,　and　so　is　seismic　design.　For　example,　influence　of　high　order　modes　is　obvious,　as　well　as　multi-support　excitation,　all　kinds　of　nonlinear　factors　and　soil　and　structure　interaction　(SSI).　It　is　necessary　to　study　on　seismic　behavior　of　a　long-span　continuous　girder　bridge.　With　the　help　of　shake　table　array　and　substructure　test　technology,　study　on　seismic　performance　of　a　long-span　continuous　girder　bridge　has　been　done　and　some　useful　conclusions　have　been　got.