We　present　a　two-dimensional　optical　coherence　vibration　tomography　(2DOCVT)　system　with　an　ultra-precision　displacement　resolution　of　similar　to　0.1　nm　that　is　capable　of　in　site　real-time　absolute　displacement　measurement　of　structural　line　vibrations.　Experimental　results　of　sinusoidal,　sweep　and　impulse　vibrations　were　reported.　The　key　figures　of　merit　such　as　the　2DOCVT　system　could　obtain　fast　line　vibration　measurement　without　scanning　and　it　also　could　be　used　to　capture　structural　modal　parameters　in　one　single　impulse　excitation　measurement　without　any　vibration　excitation　input　information,　making　it　attractive　for　the　application　in　low-frequency　vibration　measurement　and　response-only　modal　analysis.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.