A　beam-column　joint　used　in　a　modularized　prefabricated　steel　structure　is　proposed　in　this　paper　in　which　factory　welding　is　completed.　The　model　tests　and　finite　element　analysis　for　the　static　and　seismic　performance　under　monotonic　static　and　cyclic　loads　were　conducted　on　four　full-size　joints,　the　rules　of　static　behaviour,　hysteretic　behaviour,　skeleton　curve,　ductility　performance,　energy　dissipation　capacity,　rotational　capacity　and　stiffness　dissipation　were　obtained.　The　effect　of　the　chord　and　web　thickness　of　the　truss　beam　on　the　static　performance　and　seismic　capacity　of　the　joint　was　studied,　as　well　as　the　effect　of　the　weld　quality　on　the　various　performances　of　the　joint.　The　simplified　equations　of　the　welded　beam-column　joint　get　along　well　with　the　experiment　results.　The　study　showed　that　weld　quality　significantly　affects　the　failure　mode　and　various　mechanical　performances　of　the　welded　joints;　equal　strength　welds　meet　the　static　strength　requirement,　but　it　is　difficult　to　meet　the　elastoplastic　seismic　requirements.　The　rotation　stiffness　of　the　joint　is　large,　and　the　ultimate　bearing　capacity　is　high.　The　existence　of　an　axillary　plate　at　the　end　of　the　chord　significantly　improves　the　ductility　performance,　energy　dissipation　and　plastic　rotation　capacity　of　the　joint.　A　reduction　of　the　chord　and　web　thickness　of　the　truss　beam　significantly　reduces　the　ultimate　bearing　capacity　of　the　joint,　but　it　is　not　linearly　proportional　to　the　section　area　and　does　not　significantly　affect　the　ductility　performance　and　the　energy　dissipation　capacity.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.