This study was an autobiographical narrative inquiry on an art therapist's self-growth process through the researcher's tree painting work. The study goal was to find the value and meaning of mental growth through understanding self-problems over time and exploring life as an art therapist through tree paintings. Accordingly, the inquiry selected 10 artworks from the works of art therapy classes, personal artwork, and self-recording journals conducted from March 2021 to August 2023. To summarize the results, first, the growth experience as an art therapist examined through tree paintings was summarized in the process of individuation, a sense of liberation, and growth. Second, the self-growth experience interpreted through the tree picture ultimately guided the researcher as an art therapist to a path to understanding and growing clients based on self-reflection and acceptance. Based on these research results, the significance and limitations of this study were discussed.