The objective of this study is to assess the effect of art activities of young children by utilizing the art therapy techniques on the daily stress and social competence of the young children. Out of children at the age of 5 in two classes of H kindergarten in P city, the study of 25 and controlling group of 25 are allocated to make a total number of 50 study objects. After pretests on the surveyed and controlling groups, 2-3times a week, totaling 12times of experimental treatments are made by selecting the art works of easy application on the education fields for the young children. The outcome of this study is as follow. First, the surveyed group participating in the art activities based on art therapy techniques gets lower points than the controlling group in criticism-attacking circumstance, anxious-frustrated circumstance, pride-deteriorated situation and the general daily stress. Second, the surveyed group participating in the art activities based on art therapy techniques gets higher points than the controlling group in positive-social activities, anxious-contracted activities, angry-aggressive activities and the general social competency.