This study was carried out to assess the relationship between job characteristics(job strain) and psychosocial distress, and to find out the effect of social support on psychosocial distress. The study design was cross-sectional, and included 1,211 industrial workers in middle-sized city. A self-administered questionnaire measured job characteristics(jod demand, job control), and social support(coworker support, supervisor support) at work. Psychosocial distress was measured using PWI(Psychosocial Well-being Index), a 45-item self-administered instrument. Among the 1,211 respondents, the prevalence of psychosocial distress was 24.8% High job stram (high job demand + low job control) was present in 8% of the subjects. The crude odds ratio of high job strain was 4.76 (95% CI : 2.60-8.74), and those of active group and passive group were 3.81(95% CI : 1.82-3.95) and 2.64(95% CI : 1.77-3.94), respectively. The odds ratios of each group adjusted for sex, age, support, and religion were still significant. Our results supported the association between job strain and psychosocial distress. Social support at work, although significantly associated with psychosocial distress, did not modify the association between job strain and psychosocial distress.