This case report discusses a 48-year-old woman with metastatic breast cancer: T4c(10.5 cm)N2bM1,(OSS, LYM), stage IV, estrogen receptor(ER)(+), progesterone receptor(PgR)(+), human epidermal growth factor receptor-2(HER2) (-), and Ki-67 17.2%. Administration of eribulin was initiated after treatment with anthracycline and taxane. Thereafter, 28 courses of eribulin maintained a SD state for over a year and improved the quality of life(QOL). Eribulin is effective for both prolonging life and improving QOL, which are the main goals in the treatment of metastatic or recurrent cancer. Therefore, this evidence suggests that eribulin can be effective in various clinical situations.