Abstract: A new numerical method to calculate the stress concentration factors(SCF) of T-joints in welded T-tube was proposed in view of the disadvantages of the present methods.By virtue of submodel technology in ANSYS,both shell and solid elements were used to simulate joints in welded T-Tube.The welded joint models were established according to AWS specifications.In order to reflect the stress distribution along the weld toe more accurately,the weld profiles including the grinding weld toe which could mitigate stress concentration effectively were modeled.The path mapping technology was used to describe the stress distribution along the brace,and then the nominal stress and hot spot stress were used to calculate SCF through path analysis.Finally,through numerical analysis of 15 T-joints in welded tube with different parameters under axial loading,in-plane bending and out-of-plane bending,the effects of geometrical parameters on the SCF values and distributions under different kinds of load were investigated.