Owing　to　high　fatigue　life,　the　iron-based　shape　memory　alloy　(FeSMA)　buckling-restrained　braces　(BRBs)　are　emerging　as　a　promising　candidate　against　long-duration　earthquakes.　However,　the　corresponding　analysis　cannot　be　found.　Current　emphasis　is　paid　on　unveiling　the　seismic　response　differences　between　concentrically　braced　frames　(CBFs)　with　FeSMA　and　steel　BRBs　when　they　are　attacked　by　long-duration　earthquakes.　To　directly　assess　the　effect　of　earthquake　duration,　this　paper　selects　a　total　of　90　pairs　of　short-　and　long-duration　earthquake　records,　which　are　record-to-record　spectrally　equivalent　over　a　wide　range　of　fundamental　periods,　for　nonlinear　time　history　analysis.　A　benchmark　six-story　CBF　is　selected　for　demonstration　purposes.　In　the　numerical　simulation　process,　the　fatigue-induced　damage　is　particularly　considered.　A　preliminary　examination　is　first　conducted　in　the　case　study,　in　which　a　representative　pair　of　short-　and　long-duration　records　is　selected.　In　what　followed,　the　statistical　results　from　the　ground　motion　suites　are　analyzed.　This　work　not　only　highlights　the　higher　failure　risk　of　steel　BRBs　than　FeSMA　BRBs　under　long-duration　earthquakes　associated　with　maximum　considered　earthquake　hazard　level,　but　also　confirms　the　advantages　of　FeSMA　BRBs　over　steel　BRBs　in　controlling　residual　deformations.