This Research has its purpose on developing, applying and proving the effect of a group art therapy program, which helps middle-school students who have difficulty in building interpersonal relations and secure attachment to understand overall human relationships so that they can increase the level of attachment, improve self-image, and form healthy as well as effective interpersonal relations. To reach the purpose of the study, the researcher reviewed relevant literature and a group consultation model in order to conduct a pilot program targeting 8 students of 'G' middle school in Busan. The researcher developed a group art therapy program designed to enhance interpersonal relations after examining the results of the pilot program and having a professional psychological consultant review the feasibility. The program is composed of experience of a secure base, recognition of the influence of attachment experience (analysis of current situations), re-evaluation and correction of an internal working model and attachment behavioral system, positive expectation of interpersonal relations and acquisition of recognition. 22 candidates were selected from the students of 'G' middle school located in Busan, and each 11 were allocated to an experiment group and to a control group. According to the attachment type test, the candidates had problem in developing secure attachment as well as interpersonal relations and, voluntarily agreed to participate in the program. To show the differences between these two groups and to prove the effectiveness of the program, ANCOVA was processed setting the experiment group's pre-test scores as covariate by using SPSS WIN(12.0) statistics program. The results obtained by the study process are as follows. First, the attachment scores of the program participant group were significantly increased compared with those of non participant control group. Second, the interpersonal relations scores of the program participant group significantly went up compared to those of the non participant control group. Third, the self-esteem scores of the experiment group were significantly improved compared with those of non participant control group. Fourth, the school life adaptation scores of the program participant group were significantly enhanced compared with those of non participant control group. Concerning the results of the study, the group art therapy program is effective in improving the level of secure attachment and interpersonal relations of middle school students. Therefore, this program is expected to be helpful to promote positive change in personal relations of middle school students by allowing them to experience a secure base that increases the level of secure attachment, correct an internal working model, as well as obtain practical skills of building healthy and effective human relationships