This study examined emotion regulation, parental support, supervision, psychological control and marital conflict and victimization by peer harassment that affect children’s behavioral problems. The sample consisted of 412 fifth and sixth grade children. Statistics and methods used for the data analysis were percentage, frequency, Cronbach’s alpha, Factor analysis, t-test, Pearson’s correlation, and multiple Regression. Several major results were found from the analysis. First, girls had more internalized behavioral problems than boys. No sex difference was found in externalized behavioral problems. Second, boys’ and girls’ internalized and externalized behavioral problems showed positive correlations with maladaptive emotion regulation and parental psychological control. Boys’ and girls’ internalized behavioral problems and girls’ externalized behavioral problems showed negative correlations with parental support, but positive correlations with parentral marital conflict and victimization by peer harassment. Girls’ internalized and externalized behavioral problems showed negative correlations with parental supervision. Third, maladaptive emotion regulation was the most important variable predicting boys’ and girls’ externalized behavioral problems and girls’ internalized behavioral problems. Victimization by peer harassment was the most important variable predicting boys’ internalized behavioral problems.