This paper presents an experimental and numerical investigation into the compression behaviour of T-joints between S690 cold-formed circular hollow sections (CFCHS). A total of four T-joints between S690 CFCHS were tested under axial compression in brace members. A typical failure mode was observed that all joints failed in an interaction between the local plastification of the chords and overall plastic bending of the chords. Three dimensional finite element models with geometrical and material non-linearity have been established and verified after calibration against test results. Both measured geometrical dimensions and material properties of these CFCHS are incorporated into the proposed models. Both the experimental and the numerical results are compared with design resistances obtained from existing design codes, including EN 1993-1-8 and CIDECT Design Guide 1. The investigation will facilitate development of efficient design rules for resistances of T-joints between S690 CFCHS under brace axial compression.