Abstract: The fracture toughness CTOD was measured for the X80 and X65 welded joints in the brittle-ductile transition temperature. The effects of strength mis-matching and specimen geometry on the fracture behavior for welded joint were conducted by experiment. The parameters controlling brittle fracture are gotten from the fracture toughness result of standard 3 point bending specimen, then the fracture behavior of the tension specimen for the welded joint with different strength mis-matching are predicted based on the local approach. It is found that the predicted result is in a good agreement with the experiment, and the local approach gives a good description of brittle fracture even though ductile crack growth prior to final fracture occurs.