Abstract: To investigate the mechanical behavior of circular ultra-high performance concrete with coarse aggregate filled steel tube (CA-UHPCFST) slender columns under eccentric compression, 7 specimens were designed and fabricated with the consideration of slenderness ratio and eccentricity. Through eccentric compression tests, the failure modes, load-deformation curves, lateral deflection distributions, load-strain relationships, ductility and ultimate carrying capacity were analyzed. The results show that the CA-UHPCFST slender columns under eccentric compression demonstrate a buckling failure pattern, and the load-deformation curves consist of elastic, elastoplastic and descending stages. The ultimate carrying capacity of specimens is inverse proportional to the slenderness ratio and eccentricity, the ductility coefficient decreases with the slenderness ratio while increases first and then decreases with the eccentricity. The carrying capacity of specimens predicted by GB 50936−2014 is in good agreement with the experimental results. The research outcome can provide reference for further investigation and engineering application of UHPCFST members.