8　beam-column　endplate　connections　of　portal　frame　with　different　details　were　studied　by　monotonic　loading　experiments.　The　characters　of　joint　rotational　stiffness,　moment　resistance,　and　rotational　capacity　influenced　by　endplate　or　column　flange　thickness,　rib　stiffener,　extended　or　flush　types　were　tested.　The　results　show　that　setting　rib　stiffener　in　joint　panel　zone　is　essential　to　increase　the　bearing　capacity　for　joints　the　bearing　capacity　of　which　is　determined　by　buckling　of　joint　panel　zone.　Connections　without　thickening　the　endplate　or　column　flange　reflect　semi-rigid　property.　Such　features　are　more　obvious　for　flush　type　connections　comparing　extended　ones.　To　simply　thicken　the　endplate　will　not　distinctly　change　the　mechanical　properties　for　the　connections　whose　endplate　and　column　flange　are　both　non-thickened.