In a previous report, the plastic deformation behavior of a notched specimen welded between 60 kg/mm² high strength steel (HT 60) and mild steel (SM 41) has been investigated under static tension applied parallel to the weld line. Because of the asymmetry of specimen, however, it is difficult to estimate from the above experimental results the effect of a notch on the plastic strain behavior of composite weldment. In the present research, therefore, two kinds of notched specimen (SHS and HSH specimens) are used in which HT 60 and SM 41 are symmetrically arranged about the axis parallel to the direction of tensile load. Strains which occurred in the notched specimens have been analyzed experimentally by the use of strain gages and the use of a Moiré method, and stresses distributed on the net section of specimens have been calculated by incremental strain theory from the measured strains. The strain concentration is more remarkable on the notch of HT 60 sides of the HSH specimen than on that of SM 41 sides of the SHS specimen. Since the stress redistribution takes place on the SHS specimen, the stress concentration at the root of notches is lowered after the SM 41 sides begin yielding. On the contrary, the stress redistribution does not occur on the HSH specimen.