This study investigated the effects of art therapy focusing on Winnicott's Faciliatating Environment to reduce anxiety and to improve the attachment of a child. The participant of this study was a 12-years-old girl in the 5th grade of elementary school with high anxiety and peer problems due to insecure attachment with her mother. A total of 40 weekly, one-hour art therapy sessions were given from June, 2013 to July, 2014. For analysis, the researchers used the Inventory of Parent and Peer Attachment(IPPA), the Beck Anxiety Inventory(BAI), the HTP, the KFD. For qualitative analysis, all activities of each session were observed, recorded, and analyzed by the therapist. The results demonstrated that art therapy focusing on Winnicott's Faciliatating Environment is effective on reducing anxiety, improving maternal attachment and improving peer attachment. As a result of this study, art therapy focusing on Winnicott's Faciliatating Environment has a positive effect on reducing anxiety and improving mother and peer attachment.