Concrete-filled　steel　tubular　(CFST)　structures　have　several　structural　and　constructional　benefits,　which　are　widely　recognized　and　have　led　to　an　increased　use　in　modern　engineerings.　A　brief　introduction　to　application　and　research　on　concrete-filled　steel　tubes　are　introduced　in　this　paper,　several　key　issues　on　designing　CFST　structures　are　presented,　including　members　subjected　to　static　loading　and　long-term　loading;　seismic　behaviours;　fire　resistence　design　and　damage　evaluation　after　exposure　to　fire,　pre-stress　effect　in　steel　tubes　and　concrete　compaction　effect.　Some　new　types　CFST　members,　such　as　CFSTs　with　thin-walled　steel　tubes　or　high-performance　concrete　used,　concrete-filled　double　skin　steel　tubular　(CFDST)　as　well　as　FRP-confined　CFST　members　and　etc.　are　introduced.　Finally,　some　recent　reseach　developments　on　CFST　column-to-beam　connections,　frames　and　hybrid　structures　using　CFST　members　are　generally　described　in　this　paper.