Abstract: In order to determine the flutter stability of super-long-span suspension bridge with CFRP main cables during erection, 10 erection phases of a CFRP-cable suspension bridge with a main span of 3500m are analyzed by the state-space method to obtain the critical wind speed of flutter stability. The effect of stiffness reduction of stiffening girder and structural damping are discussed in detail. The effect of cross cables is also studied to improve flutter stability. It is shown that flutter stability of super-long-span suspension bridge in erection phase can be greatly improved by using both vertical and horizontal cross cables.