Abstract: A dynamic analysis model of wind-train-bridge system is established.The wind excitations of the system are the buffeting and self-excited forces simulated in time domain using measured aerodynamic coefficients and flutter derivatives.The proposed formulations are then applied to a long suspension bridge.The dynamic responses of the bridge and the train under wind action are analyzed.Results show that the lateral and rotational displacements of the bridge are dominated by wind,while the vertical displacement results from the train's gravity loading.The running safety of the train is much affected by wind: Under the wind of 30-40m/s,the offload factors,derail factors and overturn factors of the train vehicles exceed the allowances,to which great attention should be paid.