Eight　specimens　of　steel　beam　to　concrete　filled　SHS　(Square　Hollow　Section)　column　connections　stiffened　by　outside　rings　were　experimentally　studied　on　the　hysteretic　behavior　under　combined　constant　axial　load　and　cyclically　lateral　load.　The　axial　load　level　of　the　concrete　filled　SHS　columns　and　the　width　of　the　joint　stiffening　rings　are　considered　as　the　experimental　parameters　of　their　seismic　behavior.　The　results　show　that　the　axial　load　level　of　the　column　has　an　obvious　effect　on　both　the　strength　and　seismic　behavior　of　the　connections.　With　the　increase　in　axial　load　on　the　columns,　the　lateral　ultimate　strength　of　the　connections　become　lower,　and　the　ductility　in　displacement　and　the　capacity　of　energy　dissipation　also　decrease.　The　lateral　load　(P)　versus　lateral　displacement　(Δ)　hysteretic　curves　of　all　the　specimens　with　different　width　of　outside　stiffening　rings　are　of　a　plump　shuttle　shape.　The　curves　show　no　obvious　strength　deterioration　and　stiffness　degradation.　The　story　drift　ductility　index　μ　fluctuates　between　3.00　and　7.41,　the　elastic　limit　of　story　drift　angle　θy　between　2.03　[θe]　and　5.30　[θe],　the　elastic-plastic　limit　of　story　drift　angle　θu　between　1.78　[θP]　and　3.90　[θP],　and　the　equivalent　damper　coefficient　he　between　0.3576　and　0.5339.　It　can　be　concluded　that　the　tested　connections　in　the　study　demonstrate　good　seismic　performance.