This　paper　presents　the　analytical　and　experimental　dynamic　analysis　of　a　concrete-filled　steel　tubular　(CFST)　half-through　arch　bridge.　with　a　span　of　90　m,　located　at　the　center　of　Xining　City,　Qinghai　Province,　China.　A　three-dimensional　finite　element　(FE)　model　is　developed　and　an　analytical　modal　analysis　is　carried　out　to　obtain　natural　frequencies　and　mode　shapes.　Dynamic　field　testing　under　ambient　excitations　was　conducted　before　the　opening　of　the　bridge　to　traffic.　Three　independent　but　complementary　output-only　modal　identification　techniques　are　used　for　system　identification.　They　are　a　modified　single-degree-of-freedom　identification　(SDOFI)　method　and　a　peak　picking　(PP)　method　in　the　frequency　domain　and　the　stochastic　subspace　identification　(SSI)　method　in　the　time　domain.　There　is　a　good　correlation　among　the　modal　parameters　identified　from　the　three　independent　identification　techniques.　The　initial　FE　model　is　then　corrected　with　the　help　of　measured　natural　frequencies　and　mode　shapes　by　varying　some　influential　parameters　of　the　bridge　making　use　of　engneering　intuition.　The　model　thus　obtained　can　be　treated　as　the　baseline　FE　model　and　is　suitable　for　long　term　monitoring　and　safety　evaluation　of　the　bridge　in　different　severe　circumstances　such　as　earthquakes　and　wind　loading.　(C)　2004　Elsevier　Ltd.　All　rights　reserved.