This　paper　deduced　the　formulations　to　solve　the　steady-state　response　of　adjacent　buildings　linked　by　equivalent　linear　elements,　and　discussed　the　influence　of　equivalent　parameters　on　shake　amplitudes　of　sub-structures.　Based　on　the　conclusion　of　steady-state　response　analyses,　the　applicability　of　linear　friction　dampers　to　suppress　adjacent　buildings　response　under　seismic　excitation　has　been　investigated;　some　nonlinear　time-　history　analyses　have　been　performed　to　verify　the　conclusion.　The　results　indicated　that　the　ratio　of　natural　frequency　between　two　sub-structures　and　the　energy　distribution　of　earthquake　excitation　are　two　key　factors　that　determine　whether　the　linear　friction　damper　could　be　use　to　link　such　structures.　If　the　ratio　of　natural　frequency　is　significant　diversity　and　the　earthquake　excitation　has　a　broader　range　of　frequency,　the　peak　displacement　of　both　sub-structures　could　be　reduced　obviously　by　using　linear　friction　dampers.　Otherwise,　not　more　than　one　sub-structure　peak　displacement　could　be　reduced　by　the　dampers.