The finite element formulation for predicting strain distributions and weld line movements in the forming processes of tailored sheet metals is developed. The material properties of the welding zone such as strength coefficient, work-hardening exponent, and plastic anisotropic parameter are analytically obtained from those of base metals based on the tensile tests. The welding zone is modelled with the several, narrow finite elements called by weld elements. To verify the finite element formulation for tailored blanks, the forming processes of autobody door inner panel section and hemispherical dome are simulated. FEM predictions are compared and showed good agreements with experimental measurements.