For　the　past　four　decades,　researchers　have　worked　upon　and　developed　a　bracing　system.　called　the　buckling　restrained　brace　(BRB)　for　frame　braced　structures.　This　system　counteracts　compression　from　buckling　during　strong　earthquakes.　The　system　has　the　advantages　of　a　common　brace　and　damper,　providing　lateral　stiffness　to　the　structure　under　frequent　earthquakes.　Seismic　energy　can　be　dissipated　by　the　steel　core　yield,　under　both　rarely　expected　and　moderate　earthquakes.　This　paper　is　devoted　to　the　concept　of　BRB,　its　components,　characteristics,　and　its　current　deficiencies.　It　also　discusses　the　current　limitations　and　estimates　the　developing　trend　of　this　technique.　It　has　a　certain　reference　value　for　in-depth　studies　on　BRB　system.