Abstract: To investigate transverse seismic response reduction of medium-span cable-stayed bridges using yielding steel dampers, a 1/20-scale full bridge model of a typical medium-span concrete cable-stayed bridge was designed, constructed and tested on the shaking tables at Tongji University, Shanghai, China. Chi-Chi wave and site specific artificial wave were input in the transverse direction. In this test, two types of transverse seismic structural systems were considered, including fixed system and energy dissipation system with yielding steel dampers. The test results show that the seismic performance of the bridge with yielding steel dampers can significantly reduce the strains at the bottom of the tower legs and the displacement at the tower top. Therefore, the proposed energy dissipation system can be applied to the cable-stayed bridges to achieve better seismic performance.