The second series of slow notch bend test was performed to investigate the effect of residual welding stress on brittle fracture of steel. Chemical composition and mechanical properties of steel tested are shown in Table 1. The following 6 types of test specimens were prepared (Fig. 1). (1) parent metal, as rolled (2) parent metal, stress annealed at 650°C, 1 hour (3) welded specimen, as welded (4) welded specimen, stress annealed (5) welded specimen, peened at internal passes (6) welded specimen, low temperature stress relieved On each one specimen among welded specimens (3) - (6), residual stress measurement was-performed by resistance wire strain gauges. Longitudinal stress are shown in Fig. 8 and Table 5. Fracture test procedure is the same as Van der Veen test. Fracture appearance and shear fracture percentage of deposit metals are shown in Figs. 9 and 10. As seen in Figs. 13-15, the results of V-Charpy tests on as-welded and annealed deposit metals found little difference, so we can conclude that stress annealing of welded joint increases notch toughness. Peening at internal passes showed little advantage. Low temperature stress relieving rather decreased notch toughness in our case.