Abstract: The confined concrete structures are frequently used in civil engineering structures since the confinement will improve the strength and the deformability of the core concrete. In order to describe the strength and deformation characteristics of the confined concrete, a new endochronic damage constitutive model suitable for the analysis of the confined concrete is proposed in terms of endochronic theory developed by Valanis with the damage theory initiated by Mazars. In this model, the elasto-plasticity of the core concrete is described by endochronic theory, and the behavior of stiffness degeneration and strain softening due to microcrack propagation is described by isotropic damage theory. The comparison of numerical and experimental results shows the model’s validation and the comparison with other models can illustrate the model’s improvements. Finally, two structural applications are also considered: columns confined with CFRP composites and steel are analyzed.