Taking　a　twin-box　girder　bridge　with　a　slot　width　ratio　of　20%　as　an　example,　the　control　effects　of　upward　vertical　central　stabilizers　(UVCS)　and　downward　vertical　central　stabilizers　(DVCS)　on　the　bridge　were　investigated　using　CFD　simulation　and　a　series　of　wind　tunnel　tests,　respectively.　The　results　show　that　the　amplitudes　of　heaving　vortex-induced　vibration(VIV)　responses　first　increase　and　then　decrease　with　the　height　increase　of　vertical　central　stabilizers,　in　which　the　amplitudes　of　heaving　VIV　responses　for　the　UVCS　with　0.4h/H　and　the　DVCS　with　0.2h/H　were　the　smallest.　The　amplitudes　of　torsional　VIV　responses　were　enhanced　by　installing　the　UVCS　while　the　DVCS　are　helpful　to　decrease　the　torsional　responses.　In　addition,　the　results　of　the　CFD　numerical　simulation　show　that　VCS　change　the　motion　mode　of　vortex　structures　in　the　slotting　and　the　pressure　zones　on　the　upper　and　bottom　surface　of　the　leeward　side　girder.　It　is　found　that　the　optimal　control　effective　on　the　VIV　performance　is　the　DVCS　with　0.2h/H,　whereas　the　UVCS　with　0.8h/H　has　the　worst　effective　of　all　cases.　©　2019,　Editorial　Department　of　Journal　of　Tongji　University.　All　right　reserved.