The　confinement　effect　of　external　and　internal　steel　tubes　on　sandwiched　concrete　in　concrete-filled　double-skin　circular　steel　tubular　(CFDST)　short　columns　has　a　significant　impact　on　the　compressive　strength　and　ductility　of　columns.　Limited　researches　on　CFDST　columns　have　only　considered　the　influences　of　a　part　of　column　parameters　on　the　confinement　effect,　leading　to　the　absence　of　appropriate　compressive　strength　formulas　in　international　standards.　To　comprehend　the　compressive　behavior　of　circular　CFDST　short　columns　and　suitably　evaluate　their　compressive　strength　for　practical　engineering　design,　it　is　necessary　to　further　launch　the　experiments　on　circular　CFDST　short　columns　and　develop　a　suitable　estimated　formula　for　their　compressive　strength.　The　purpose　of　this　paper　is　to　develop　a　simple　and　accurate　formula　for　predicting　the　compressive　strength　of　axially　loaded　CFDST　short　circular　columns　with　a　wide　range　of　parameters.　A　total　of　24　specimens　with　outer　and　inner　circular　carbon　steel　tubes　that　withstand　axial　compression　were　tested.　A　new　confinement　coefficient　reflecting　the　confinement　effect　of　concrete　strength　in　CFDST　columns　was　proposed　on　the　basis　of　the　test　data　in　the　present　paper　and　data　collected　from　literature.　Utilizing　the　proposed　confinement　coefficient,　a　novel　strength　design　formula　was　developed　to　estimate　the　compressive　strength　of　CFDST　short　circular　columns.　It　shows　that　the　proposed　confinement　coefficient　can　reasonably　reflect　the　interaction　effect　between　the　sandwiched　concrete　and　steel　tubes,　and　the　formula　suggested　in　this　paper　offers　better　predictions　of　the　compressive　strength　than　current　design　formulas.　(C)　2020　Elsevier　Ltd.　All　rights　reserved.