The aim of this paper is to study elasto-plastic behavior of the doubler plate reinforced tubular T-joints (DP-T-joints) subjected to axial tension or compression loading at the top of brace. Finite-element method is adopted in the numerical parametric studies to evaluate the ultimate strength of DP-T-joints. To verify numerical analysis, a typical full-scale doubler plate reinforced tubular T joints experimental study has been modeled using ABAQUS package. The load-displacement curves of the numerical results agree with the experiment curve very well. Then, affect of parameter (doubler plate width parameter α, doubler plate length parameter Δ, doubler plate to chord wall thickness ratio λ) on the elasto-plastic behavior has been investigated.