We investigated the association between the oxidative stress and the concentration of heavy metals in blood among welders. The study subjects were male manual CO2 welders(N=127) exposed to several heavy metals. The age distribution was from 20 to 63 (GM=33.7) and the geometric mean(GM) of work duration was 4.2 years. We analyze the level of blood lead, cadmium, managese and chromium which was related with the oxidative stress in the animal studies. Blood selenuim, plasma malondialdehyde (MDA), plasma alpha-tocopheol and orythrocyte superoxide dismutase (SOD) were analyzed as biological markers of the oxidative stress. The results of univariate analysis showed that the plasma MDA was significantly correlated with D-tocopherol (r=0.327) and blood selenium (r=0.313) concentration. But we could not find out any relationship between the erythrocyte SOD activities and those metal concentrations. Neither smoking nor alcohol consumption was related to the level of heavy metals and the oxidative stress biomarkers. As the results of multiple regression analysis with stepwise selection method, 1) the change of MDA level were dependant with the level of alpha-tocopherol and blood selenium concentration (R2=19.7), 2) the plasma alpha-tocopherol level was dependant with MDA and blood chromium concentration (R2=15.6), 3) in case of erythrocyte SOD activity, only the duration of work was significantly selected.