Objective: This study aimed to find out whether concern for children mediates the impact of parenting competence on the anger expression of mothers with young children. Methods: Subjects consisted of 219 mothers with children aged 3 to 6 years old attending kindergartens and daycare centers. The motehrs were given 3 rating scales about parenting competence, concerns about their children, and anger expression. The Parental Anger Scales measuring anger expression consisted of sub-factors such as situational anger, impulsive behavior, and difficulty of anger control. Results: Using the data collected, correlation analysis and the regression analysis procedure by Baron & Kenny(1968) were conducted; the significance of the mediating effects was verified by the Sobel test. First, the study found that there were significant positive correlations between mother s parenting competence, concern about children, and anger expression. Second, mothers’ concern about their children had partial mediating effects on the relationships between parenting competence and overall anger expression, situational anger and impulsive behavior, and a complete mediating effect on the relationship between parenting competence and difficulty with anger control. Conclusion/Implications: These results were discussed in terms of the approach and content of parent education to help parents with young children control their anger.