High-strength　steel　and　concrete　materials　(i.e.,　steel　with　yield　stress　F-y　＞　525　MPa　and　concrete　with　compressive　strength　f＇(c)　＞　70　MPa)　have　been　applied　in　various　types　of　structures　because　they　can　increase　the　resistance　and　space　efficiency　of　the　structure.　However,　the　AISC　Specification　(AISC　360-16)　does　not　permit　the　use　of　high-strength　materials　in　concrete-filled　steel　tube　(CFT)　members　due　to　a　lack　of　adequate　research.　This　paper　aims　at　investigating　the　behavior　of　high-strength　CFT　long　columns　and　evaluating　the　applicability　of　current　design　equations　for　high-strength　rectangular　CFT　long　columns.　Firstly,　an　experimental　database　including　74　tests　of　high-strength　rectangular　CFT　long　columns　was　compiled　and　gaps　in　the　database　were　identified.　Then,　finite　element　(FE)　models　were　developed　and　benchmarked　for　parametric　studies.　The　effects　of　width-to-thickness　ratio　of　the　steel　tube,　yield　stress　of　steel,　compressive　strength　of　concrete,　and　length-to-depth　ratio　of　the　member　were　investigated.　Finally,　new　design　equations　for　high-strength　rectangular　CFT　long　columns　were　proposed　based　on　the　modified　slenderness　reduction　factor　in　AISC　360-16.