Abstract: The effects of strength mis-matching and specimen geometry on the resistance behavior to ductile crack growth for welded joint were conducted by 3-D FE analysis considering the micro-plastic damage.The resistance curves were measured with the standard three point bending specimens and the double edge notched tension specimens at different mis-matching welded joint.The parameters controlling ductile crack growth are gotten from the resistance curve of standard 3 point bending specimen,then the resistance curves of the tension specimens for the welded joint with different strength mis-matching are predicted based on the cell model.It is found that the predicted result is in a good agreement with the experiment,and the cell model gives a good description of ductile crack growth.