This study aimed to investigate the effects of art therapy on the reduction of stress and abnormal behaviors of children in dual-income families. The subject of this study was a child of a dual-income family who is mainly having abnormal behaviors at home and complains of a high level of stress. The client, a fourth-grade girl at D Elementary School in S. City, participated in the program for 50 minutes once a week for 20 sessions. The measurement tools were K-CBCL 6-18, which was used for the test to measure the abnormal behavior of school-aged children and adolescents, the stress perception test used by Joo Eun-sook (2005), and the projection test for the person in the rain. The results of this study were as follows: First, all of sub-criteria of the stress test were reduced as a whole, in a positive way. Second, the sub-criteria of the abnormal behavior test showed a decrease in violation and anxiety depression scores. These results show that the reduction of stress and abnormal behaviors in children can be achieved through art therapy so that children have smoother interactions with their families and can express and stay aware of their own emotions. In other words, art therapy helps children develop the ability to deal with their anger, stress, and abnormal behavior. Based on these results, the implications and limitations of this study are discussed.