Abstract: A seismic response model of long span concrete filled steel tube (CFST) arch bridge is set up. Taking a bridge of 76+360+76 m span concrete filled steel tube tied arch bridge as an example, the seismic response behavior is systematically studied. The results show that in the apex of arch the response member forces are low, while response horizontal displacement is maximum, forces in the springing of main arch rib are relatively large, and the non-synchronous support motion due to the traveling seismic wave may have a significant effect on the response. They tend to increase the axial-force of arch rib and vertical displacement and decrease the horizontal displacement.