Abstract: Taking Xiangshangang Bridge and Second Jiaojiang Bridge for examples, the influence of wind fairing angles on the vortex-induced vibrations and flutter performances of closed and semi-closed box decks were investigated with a wind tunnel test aided with the computational fluid dynamics (CFD) method. The results show that the vortex-induced vibration performances could be improved via sharpening wind fairings without the flutter stability being decreased. However, the vibration mitigation effect is more significant on the closed box deck than that on the semi-closed deck. CFD simulations show that the variation of wind fairing angles could change the flow pattern around the bridge deck. The pattern of vortices shedding from the closed box deck is simple and inerratic, but it is complex when shedding from the semi-closed box deck.