This study is a single-case art therapy study conducted to examine two research aims in a child who, after being diagnosed with dyslexia due to persistent learning difficulties, exhibited emotional and psychological difficulties such as anxiety and withdrawal. The first aim was to explore the process of emotional-psychological change across treatment sessions. The second aim was to examine the effects of the art therapy program on self-esteem. The participant was one fourth-grade boy living in City A. The program consisted of 14 sessions in total, including one pre-assessment session, twelve art therapy sessions, and one post-assessment session, and was implemented for 50 minutes per session over approximately nine weeks (from June 28 to August 31, 2019). Because peer conflict, withdrawal, and anxiety had intensified after the child entered the fourth grade, twice-weekly intensive sessions were initially applied to promote rapid emotional-psychological stability and to establish a therapeutic relationship. Subsequently, as emotional-psychological changes were observed and judged to have emerged, the frequency was adjusted to once a week to reduce the child's burden and to help maintain the therapeutic changes in a stable manner. In accordance with the two research questions, session-by-session observation records, verbatim transcripts, and artworks were qualitatively analyzed by stage (initial, middle 1, middle 2, and final) to trace the emotional-psychological change process, and pre- and post-test scores on the self-esteem scale were compared. Regarding Research Question 1, the participant's emotional-psychological state shifted from anxiety, withdrawal, and defensive responses in the initial stage to expanded emotional expression and reduced tension in the middle stage, and then to greater stability, self-expression, and recognition of personal strengths in the later stage. Regarding Research Question 2, the total self-esteem score increased from 87 to 105, and all subdomains-general, social, family, and academic self-esteem-improved. This study is meaningful in that it systematically describes both the emotional-psychological change process and changes in self-esteem, thereby offering foundational data for clinical practice with children with dyslexia.