The　ambient　vibration　field　testing　of　a　skewed　T-girder　bridge,　called　＇Yuanland　bridge＇　on　the　G107　line　of　national　highway　is　firstly　carried　out.　The　peak　picking　(PP)　method　in　frequency　domain　and　the　stochastic　sub-space　identification　(SSI)　method　in　time　domain　are　applied　to　identify　the　modal　parameters　of　the　bridge,　such　as　frequencies,　modal　shape,　and　damping　ratios.　Based　on　its　3-D　finite　element　(FE)　model　constructed　using　ANSYS　program,　its　theoretical　modal　analysis　is　performed.　The　results　from　FE　modi　are　compared　with　those　from　field　testing.　The　dynamic　behavior　of　this　kind　of　bridge　with　different　skewed　angles　and　same　spans　are　compared　to　reveal　the　dynamic　characteristics　of　the　skewed　T-girder　bridge.