Tuned　liquid　damper　(TLD)　is　a　typical　passive　device　to　control　structural　response　under　wind　and　earthquake　excitation.　At　present,　TLD　is　often　used　to　control　single-mode　of　structure.　Hence,　the　design　theory　of　TLD　is　often　based　on　single-degree　of　freedom　(SDOF)　system　in　frequency　domain,　which　is　hard　to　accurately　evaluate　seismic　performance　of　TLD-installed　multi-degree　of　freedoms　(MDOFs)　with　consideration　of　higher　mode.　In　this　work,　a　frequency　domain　transfer　function　for　TLD　controlled　MDOFs　system　is　established　through　the　concept　of　substructure　to　evaluate　overall　seismic　performance　of　TLD-installed　MDOFs.　The　accuracy　of　the　transfer　function　is　verified　by　real-time　hybrid　testing.　Using　this　transfer　function,　the　effect　of　TLD　on　the　seismic　performance　of　MDOFs　was　discussed　in　frequency　domain　by　parametric　analysis.　The　analytical　results　indicated　that,　based　on　the　design　theory　for　single-mode,　the　TLD　with　large　mass　ratio　cannot　enhance　the　seismic　performance　effectively　comparing　with　small　mass　ratio.　In　order　to　improve　the　control　efficiency　of　relatively　large　mass　TLD,　a　design　method　for　multi-mode　control　is　established　based　on　the　developed　frequency　domain　transfer　function.　The　simulation　results　showed　that,　with　same　TLD　mass,　the　multi-mode　method　performed　smaller　structural　acceleration　response　and　similar　displacement　response　relative　to　the　single　mode　method.