Abstract: The long span bridge over Hangzhou Gulf is the longest across-sea bridge in the world.It mainly consists of the south-channel and the north-channel sections.Aerodynamic stability is one of the most important factors considered in the design and construction of the bridge.The dynamic analyses of the south-channel single-tower cable-stayed bridge during construction and service are conducted by adopting a single beam mechanical model.Vibration and aerostatic coefficient tests were also conducted using wind tunnel with section models.The critical flutter wind speed,flutter derivatives,vortex-induced vibration,buffeting response and aerostatic coefficients were measured,and wind-resistant property of the bridge is assessed based on the experimental results.The results show that the bridge has good aerodynamic stability.