Viscous　dampers　have　been　widely　used　for　seismic　mitigation　of　long-span　double-tower　cable-stayed　bridges,　and　the　effectiveness　of　seismic　mitigation　of　cable-stayed　bridges　depends　on　the　selection　of　dampers.　Parametric　analyses　are　necessary　to　determine　the　parameters　of　the　viscous　dampers.　To　determine　the　optimal　parameters　effectively,　response　surface　method　is　used　to　optimize　dampers＇　parameters　in　this　paper.　Full-bridge　shaking　table　tests　are　conducted　for　verification　of　the　calculating　method　presented.　It　can　be　concluded　that　the　response　surface　method　can　satisfy　the　requirement　for　precision　of　optimization　since　simple　algebraic　formulae　can　be　used　to　accurately　fit　the　complicated　relationship　between　design　variables　and　response　ones.　This　outcome　not　only　simplifies　the　process　of　parameter　analyses,　but　also　overcomes　the　blindness　of　determining　the　optimal　parameters.　It　is　thus　expected　that　the　reported　response　surface　method　has　great　application　potential　for　the　preliminary　design.