The　use　of　concrete　filled　composite　columns　has　become　increasingly　popular　in　civil　engineering.　Only　in　China,　it　is　reported　that　more　than　twenty-four　high-rise　buildings　and　two　hundred　arch　bridges　have　been　built　due　to　their　high　strength　and　ductility,　as　well　as　large　energy-absorption　capacity.　In　the　past,　much　progress　had　been　made　on　the　research　of　the　static　behaviors　of　concrete　filled　steel　SHS　(Square　Hollow　Section)　columns,　however,　limited　information　is　available　on　experimental　behaviors　of　these　columns　when　subjected　to　both　axial　and　horizontal　loading.　In　this　paper,　two　series　of　experiments　were　conducted,　the　specimens　of　the　first　series　were　short　columns　subjected　to　cyclic　shearing　force　as　well　as　constant　axial　force,　whereas　the　specimens　of　the　second　series　were　longer　mainly　subjected　to　a　combination　of　constant　axial　load　and　cyclically　flexural　loads.　The　main　parameters　varied　in　the　tests　are　axial　load　ratio　and　tube　width　to　thickness　ratio.　Compared　to　conventional　reinforced　concrete　columns,　the　SHS　specimens　exhibit　richer　energy-dissipation　characteristics.　The　moment　capacities　of　SHS　beam-columns　can　be　predicted　with　reasonable　accuracy　from　simplified　interaction　curves.　The　experimental　load　versus　hysteretic　defection　relations　are　compared　to　those　predicted　by　integral　method　presented　earlier,　and　satisfactorily　agreements　are　gained.