To　study　the　mechanical　behavior　of　recycled　aggregate　concrete-filled　circular　steel　tube　(RACFCST)　columns　under　eccentric　loading,　15　specimens　with　different　replacement　ratio　of　recycled　coarse　aggregate,　slenderness　ratio　and　eccentricity　were　tested　under　the　monotonic　static　loading.　The　failure　modes　were　observed,　and　then　the　curve　of　the　entire　loading　process　as　well　as　the　strain　distribution　over　the　cross　section　were　obtained.　The　influence　of　varying　parameters　on　the　mechanical　behavior　of　RACFCST　columns　was　analyzed,　and　then　the　ultimate　bearing　capacity　was　calculated　using　existing　theories.　It　is　shown　that　about　the　failure　process　and　failure　mode　RACFCST　columns　are　similar　to　the　eccentrically　loaded　concrete-filled　circular　steel　tube　columns,　in　which　the　circular　steel　tube　fails　eventually　in　the　drum-like　buckling　mode.　It　is　found　that　RACFCST　columns　have　high　bearing　capacity　and　good　deformation　performance,　and　the　influences　of　eccentricity　and　slenderness　ratio　on　the　mechanical　behavior　of　RACFCST　columns　are　obvious,　while　the　influence　of　aggregate　replacement　ratio　is　comparatively　unobvious.