For typical tubular T-joint, the common failure generally occurs near the weld toe on the chord surface due to the fact that the stiffness of the chord in radial direction is much smaller than that of the brace in axial direction. In this paper, the static strength of tubular T-joints is improved by filling concrete into the chord. The finite element method is used to investigate the improving effeciency of the static strength for tubular T-joints with filling concrete in the chord under axial compression and tension. Firstly, 6 T-joint models were analyzed to prove that filling concrete in the chord is effective to increase the static strength and the stiffness of T-joints with hollow section. Afterwards, based on the analyzing mechanism for CFCT T-joint under axial compression and tension, the different performances under axial compression and tension between circle hollow tubular T-joint and CFCT T-joint were clarified, and the different failure modes for tubular T-joints with hollow section and CFCT T-joints were compared and analyzed.