The　steel-concrete　composite　slim　floors,　with　the　concrete　slab　laid　on　the　lower　flange　of　the　steel　section　and　the　majority　of　steel　beam　encased　in　concrete　slab,　ensure　the　bonding　force　between　steel　and　concrete　and　make　them　working　well　together.　This　paper　presents　an　experimental　study　on　a　full-scale　two-storey,　two-bay　by　one-bay　steel-concrete　composite　slim　floor　that　was　subjected　to　horizontal　pseudo-dynamic　loading.　Based　on　the　test　results,　the　specimen　shows　high　loading　capacity　and　good　ductility.　The　skeleton　curves,　structural　deformation　and　the　failure　mode　obtained　from　the　pseudo-static　loading　tests　are　provided.　Suggestions　on　the　improvement　of　the　composite　beam-column　connection　is　proposed.