Abstract: In order to investigate the fatigue performance of a new cable-to-girder anchorage in a cable-stayed bridge with steel box girder, different force transfer paths and mechanic behaviors of two types of anchorages connecting anchor-plate with web of box girder or anchor-plate with top plate of box girder were analyzed for different joint structures between anchor-plate and main girder. Software ANSYS was used to the simulation of anchorage zone to obtain the distribution and concentration degree of stresses. Fatigue test of a full-scale model for the anchorage zone was designed and carried out. By combining simulation analysis with experiment results, fatigue performance of connect welds in the new anchorage system under cyclic load was investigated. Theoretical and experimental results show that fatigue strength of the new anchorage system can meet the need of design. Connecting anchor-plate with web of box girder makes stress concentration reduce, the allowable fatigue stress of weld details increase and the fatigue performance of anchorage zone be improved.