Objectives:This study investigated the relationship among child's behavior problems, maternal depression, and parenting stress in children with psychiatric diagnoses and their mothers, and the effect of these variables to the mothers' parenting stress. Methods:Seventy-three children(31 externalizing, 24 internalizing, 18 mixed) and their mothers were involved in this study. The mothers of three groups completed MMPI, KPI-C(Korean Personality Inventory for Children), and PSI(Parenting Stress Index). To investigate the relationships among each variables, ANOVA, Pearson correlation, stepwise regression analysis were performed. Results:There was no significant difference in maternal depression among three groups of children. In 2-Way ANOVA, main effect of maternal depression was statistically significant on depression, parent health, and relationship with spouse subfactor in parent domain, parent domain total, and overall parenting stress. But the main effect of child group was statistically significant on distractability/hyperactivity subfactor in child domain only. In regression analysis, maternal depression explained the parent domain of parenting stress most effectively, and child's hyperactivity and anxiety explained the child domain of parenting stress significantly. Conclusion:These findings suggest that it is important to intervene maternal depression to reduce the parenting stress, along with the treatment of the child's behavior problems.