The elongating of cablestayed bridge brings a series of aerodynamic problems. First of all, geometric nonlinear effect of extreme long cable is much more significant for cablestayed bridge spanning over one thousand meters. Lateral static wind load will generate additional displacement of long cables, which causes the decrease of supporting rigidity of the whole bridge and the change of dynamic properties. Wind load, being the controlling load in the design of cablestayed bridge, is a critical problem and needs to be solved. Meanwhile, research on suitable system between pylon and deck indicates fixedfixed connection system is an effective way for improvement performance of cablestayed bridges under longitudinal wind load. In order to obtain aerodynamic parameters of cablestayed bridge spanning over one thousand meters, identification method for flutter derivatives of full bridge aeroelastic model is developed in this paper. Furthermore, vortex induced vibration and Reynolds number effect are detailed discussed.