This work reports the results of a numerical investigation of the flange and web plates of cold-formed steel I-section under axial compression. The column cross-section dimensions and lengths selected by means of sequences of ‘trial & error’ elastic buckling analysis using Finite Strip Method CUFSM. Some instability phenomena like local, distortional and global-buckling arises. Then, the paper (i) summarizes the results obtained in a recent experimental investigation carried out by Santos et al (2012) and presented numerical analysis of columns by means of ANSYS 12. Finally, the ultimate strength and failure modes of cold formed steel flange and web plates and their interaction are considered by analysing in ANSYS 12.