The purpose of this study was to examine the meaning of Open Studio Process (OSP) experience by art therapists. The subjects of the study were 20 art therapists who obtained a master's or doctoral degree in art therapy, OSP was conducted once a week, 120 minutes, for a total of 6 sessions from June to November 2021. Due to the COVID-19 pandemic situation, research was conducted through an online conference platform such as Zoom. To find out the meaning of OSP experience, interviews were conducted with OSP participants, and data such as interview recording files, participants' art work images, participants' writing and research journals were analyzed through a qualitative case study method. Based on Glaser and Strauss (2011), it was classified into six upper categories and 15 sub-categories. The upper categories of OSP experience of art therapists are “OSP structure and rules give me a sense of stability and focus on me,” “Taking a break from a busy routine to take care of yourself,” “The relationship with art and discomfort has changed,” “Staying and expressing as it flows and meeting the personality,” “Writing recognizes the direction of life and listens to images,” and “Confident in art and newly recognized the role of art therapist,” Based on these research results, the significance and limitations of the study were discussed.