Currently, the cold-formed Steel sections (CFS) are increasingly used in light and mid-height buildings. So, this research examined the axial compression behavior of CFS thin-walled Zee-shaped section under pure axial monotonic loading. This study conducted full-scale tests on three specimens to investigate the three main modes of failure: local buckling, distortion buckling, and global buckling modes. The specimens were selected from CFS Zee sections with 600mm, 1000mm, and 2500mm. The imperfection of the CFS sections was captured by the 3D scanning before testing and implementation in the FE models. Then, the pure axial load was applied monotonic. The failure modes and axial capacity are discussed in detail. In addition, this research investigated the axial load-displacement responses and the axial load capacity. The energy dissipation with strength degradation was thoroughly investigated. A Finite Element Model (FEM) was conducted and verified by the experimental results. Finally, the FEM analysis was extended to study the behavior of the Zee section with a different range of dimensions to predict the section parameters' behavior under axial monotonic load.