An　optical　coherence　tomography-based　structural　vibration　sensor　system　is　reported.　The　system　employs　a　halogen　tungsten　lamp　as　the　low-coherence　light　source　and　a　broadband　CCD-based　spectrometer　as　the　detector.　Unlike　traditional　piezoelectric　accelerometer,　the　sensor　system　is　non-contact　and　it　measures　the　surface　displacement　of　a　sample　directly.　Due　to　the　extreme　broadband　of　the　thermal　light,　the　sensor　system　can　offer　a　high　axial　resolution　of　0.9　μm.　Experimental　result　demonstrated　that　both　the　vibration　amplitude　and　frequency　can　be　quantified　by　the　current　sensor　system.　The　measurable　frequency　range　currently　achieved　is　0-250　Hz,　and　this　could　be　easily　increased　to　a　few　KHz　if　the　latest　CCD-based　spectrometer　is　employed.　We　believe　that　the　developed　sensor　system　is　an　ideal　tool　for　in-situ　monitoring　of　these　low-frequency　micro-vibrations　in　high-precision　manufacturing　and　measuring　system.　©　2010　IEEE.