This　paper　proposes　an　innovative　beam-to-column　T-stub　connection　with　inserted　plates　to　overcome　the　problems　that　the　traditional　connections　are　prone　to　brittle　failure　and　the　improved　ones　are　not　convenient　to　repair　after　damage.　Three　different　specimens　were　designed,　fabricated　and　tested　by　quasi-static　experiments,　which　included　a　steel　joint　without　a　concrete　floor　slab,　a　steel　joint　with　a　concrete　floor　slab　and　a　traditional　T-stub　connected　joint　without　a　concrete　floor　slab.　The　seismic　behaviors,　such　as　the　stiffness,　the　bearing　capacity,　the　ductility,　the　hysteretic　behavior,　the　energy　dissipation　capacity　and　failure　mode,　etc.,　were　studied.　Moreover,　after　repaired　by　replacing　the　destroyed　bottom　T-stub,　the　joint　was　tested　once　again.　The　results　indicate　that　T-stub　connected　joints　with　inserted　plates　can　provide　good　hysteretic　behavior　and　energy　dissipation　capacity　under　a　reciprocate　load.　The　beam　and　column　do　not　yield　after　the　connection　failure,　and　the　rotational　center　of　the　connection　locates　near　the　top　of　beam　flange,　which　can　guarantee　that　the　upper　T-stub　is　not　destroyed　and　the　concrete　floor　slab　is　protected　from　severe　damage.　The　concrete　floor　slab　can　improve　the　initial　stiffness　and　capacity　of　connections　under　the　sagging　moment,　and　make　the　neutral　axis　move　up.　There　is　no　obvious　difference　in　the　hysteretic　behavior　between　the　undamaged　connection　and　the　repaired　one.