In this article, through changing the parameters of the slenderness ratio lambda and axial compression ratio of n, the eight experimental study of steel tube concrete bending members with circular cross section. To explore different slenderness ratio of lambda concrete-filled steel tube under low cycle loading, the damage form of artifacts, deflection change, the relationship between the load and strain, load (P) and displacement (Δ) curve, the axial deformation and stiffness degradation curve, displacement ductility coefficient and the change of parameters such as energy consumption, thus further elastic-plastic seismic response analysis of concrete filled steel tubular structures. Got by test data of load P - displacement Δ relation curve and stiffness degradation curve, the displacement ductility coefficient, the total energy consumption. To get round steel tube reinforced concrete member seismic performance is good, the ductility damage.