Abstract: A new damper system called Lever Mass Damper (LMD) for vibration control of inclined cables on cable-stayed bridges is developed, and the structure, damping principle of LMD for vibration suppression are discussed as well. The damping performance of an LMD attached to a stay cable is investigated by solving complex eigenvalue problem with Nonlinear FEM. Compared with an oil damper for cable vibration control, except the 1st mode, LMD can provide higher modal damping ratios and has better performance for mitigation of cable vibration.