Abstract: Welding stress in electron beam welding joint of TiAl intermetalics plates,as well as the relationship between stress distribution and crack characteristic were numerical stimulated using thermo-elastic-plastic finite element method.The results showed that stress σ_x along welding direction was tensile stress,and which was a relatively high level in central weld.With the highest value of 390 MPa,σ_x in the cross section in central weld was tensile stress and it came to the largest value of 415 MPa in HAZ.In the same section,σ_y perpendicular to welding direction was also tensile stress and the largest value was approximately to 160 MPa at the site 1.9 mm away from weld center line.The highest tensile strength of the joints welded under different heat inputs was 304.7 MPa.Fracture occured near HAZ,e.g.the place where the residul stress value was the largest from the numerical simulation results.