OBJECTIVES: This research is designed to reveal Quality of life of Korean patients with metastatic breast cancer for cancer treatments. METHODS: This is a multicenter, cross-sectional study in breast cancer patients receiving palliative chemotherapy. Total 199 patients with metastatic breast cancer were interviewed from 4 centers. Clinical, socio-demographic, and quality of life data were collected. Subjects completed a face-to-face interview with trained interviewer to assess their health status for breast cancer treatment. Patients recalled the before diagnosis status under current situation. we used the three methods to evaluate the health status; EORTC QLQ-C30, BR-23, EQ-5D. RESULTS: Overall utility weights for EORTC QLQ C30 and EQ-5D was 0.81 and 0.78 respectively(before diagnosis). It is higher than those of current (EORTC QLQ-C30: 0.54, EQ-5D: 0.60). the patients who are before diagnosis estimated higher functioning score compared to current. (physical functioning scale ; before cancer: 92.8, current 65.3) The higher the score is, the better patients’ function is. Symptom scale scores are the similar with functioning scale scores. The higher the score is, the worse the symptom is. before cancer status has lower symptom scale scores than current. (fatigue symptom scale; Before cancer: 25.2, current: 48.5)  BR 23 scale , there were deteriorations in patients for all domains compared to scores of before cancer patients. Especially, patient’ current body image score is significantly lower than that of before diagnosis patients. (before diagnosis: 91.4, current: 46.4) CONCLUSIONS: There are few study of Quality of life in breast cancer patients. It is meaningful that this study provided the utility weights for breast cancer patients in Korea.