Abstract: In order to study the effect of signature turbulence on the aerostatic stability of long-span bridges, a model for signature turbulence aerodynamic-force was proposed. An approach for analyzing the effect of signature turbulence on the aerostatic stability was also put forward. The time-histories of aerodynamic force coefficients were simulated based on the spectra gained in wind tunnel tests of a sectional model. The displacement responses of Xihoumen Bridge were then calculated using the dynamic FEM method. The results show that the bridge deck vibrates with a small amplitude in the vicinity of an aerostatic equilibrium configuration, which means the effect of signature turbulence on aerostatic stability is unremarkable. Signature turbulence is a narrow-band random process. The energy mainly concentrates near a certain frequency which is much higher than the fundamental frequency of Xihoumen Bridge. As a result, signature turbulence cannot induce a vibration with a large amplitude.