Self-help group program is an elective procedure intended to improve the quality of life of women undergoing mastectomy. The purpose of this study is explore effects of the self-help group program for QOL after mastectomy. 40 Women who had undergone mastectomies between stagel to 3 were recruited. Subjects of experimental group attended the self-help group for 4 weeks. Data were collected by self-reporting questionnaire. QOL was assessed using the Quality of Life Scale(QLS) translated by Kwon(1990). As a results, no significant differences were found between experimental and control group in changes of QOL. But, experimental group increased QOL score. In conclusions, when the self-help group program is provided to the patients with breast cancer, it can be helpful for promoting QOL and emotional support, even no statistical difference. For the further study, repeated researched with appropriate duration of intervention is suggested. Significant anxiety about their disease and fear of recurrence will be persisted despite intervention.