Abstract: The axial compression behaviour of circular carbon fiber reinforced polymer (CFRP) confined reactive powder concrete (RPC) filled steel tube stub columns was investigated. The mechanical tests of 12 CFRP confined steel tube-RPC stub columns, 4 steel tube-RPC stub columns and 4 steel tube stub columns were performed with the number of the CFRP layers and the steel tube thickness as parameters. The load-displacement curves were used to analyze the effects of the CFRP layer number and the steel tube thickness on the ultimate load and deformation capacity of the specimens. Subsequently, the performance indicators such as improvement coefficient, CFRP strain efficiency and ductility coefficient were discussed. Finally, a model of CFRP confined steel tube-RPC stub columns was proposed by increasing the coefficient associated confinement ratio. The experimental results indicate that the bearing capacity and deformation capacity of the CFRP confined steel tube-RPC stub columns are significantly improved by CFRP. In contrast to the CFRP confined concrete filled steel tube (CFRP confined steel tube-C), the CFRP confined steel tube-RPC exhibites a decrease in CFRP strain efficiency, and its ductility is worse than the CFRP confined steel tube-C. Based on the bearing capacity of steel tube-RPC, a practical model for calculating the bearing capacity of CFRP confined steel tube-RPC stub columns is proposed.