The purpose of this study was to verify the effect of collage art therapy on the emotional awareness and expression of maladjusted children in school. The participants of this study were 14 children between the ages of 11 and 13 implementing the School Adaptation Scale(K-MISA) and randomly assigned to the control group and the experimental group. The therapy consisted of 12 sessions and was conducted twice a week for 40 minutes in each session from September to November 2020 for the experimental group. For measurement, the Emotional Expression Scale for Children(EESC) was adopted. To verify the effect, mixed design ANOVA was performed with the pre-test and post-test scores of the control group and the experimental group. By extracting the emotional expressions from verbatim records, the change in emotional expression and its content in each session were analyzed qualitatively. In the results of the study, the difficulty of emotional recognition and emotional expression significantly decreased and its effect sustained. The frequency of emotional expression was increased as the session progressed, and the tendency of self-emotional recognition, expression improvement, and emotional understanding of others increased. Based on these research results, the significance and limitations of this study were discussed.