The purpose of this study was to examine the relationships among marital conflict, depression, parenting stress, and parenting behavior of mothers. The data from mothers of 1703 4-year-old children participating in the Panel Study of Korean Children was analyzed. Findings of this study from structural equation modeling analysis indicated that marital conflict was associated positively to depression of mothers. Depression significantly predicted parenting stress and parenting behavior. Parenting stress had a strong effect on parenting behavior. This study showed that depression mediated the relationships between marital conflict and parenting stress. The relationships between marital conflict and parenting behavior were mediated by depression and parenting stress.