Studies　show　that　proper　elastic　viscous　damper　between　the　tower　and　girder　can　improve　the　seismic　behavior　of　cable-stayed　bridge.　However,　conclusions　at　present　are　mostly　drawn　from　some　specific　engineering　projects　without　considering　the　influence　of　different　relative　height　of　deck　on　viscous　damper＇s　shock　reduction　effect.　By　changing　the　height　of　lower　towers　to　alter　the　relative　height　of　deck,　the　influence　of　relative　height　of　deck　on　tower-girder　viscous　damper＇s　shock　reduction　effect　was　analysed　based　on　a　certain　cable-stayed　bridge　model.　According　to　the　study,　it　is　shown　that　the　relative　height　of　deck　of　cable-stayed　bridge　has　an　outstanding　influence　on　the　damper＇s　optimal　parameters　and　the　optimum　shock　reduction　effect.　©,　2015,　Chinese　Vibration　Engineering　Society.　All　right　reserved.