Inclusion Criteria:  Age ≥ 18 years old, voluntary consent and signed written informed consent. ECOG 0~2. Diagnosis of locally advanced (stage IIIB or IIIC) or metastatic (stage IV) breast cancer. At least one measurable disease lesion before treatment. Never receive Eribulin Mesylate treatment before recruitment. Anticipated survival time is longer than three months. Pathological and IHC reports for ER, PR, HER2 and Ki67 are available. For women with fertility, the pregnancy test before administration was negative, and agreed to take appropriate measures to avoid pregnancy during the study treatment and at least half a year after the end of treatment; Men agreed to take appropriate contraceptive measures during the study treatment and at least half a year after the end of the treatment. There are traceable medical records during treatment.  Exclusion Criteria:  Pregnant or lactating women. Active infection requiring systemic treatment。 HIV positive Suffering from or suspected of suffering from central nervous system diseases. Serious heart disease. Patients with brain or meningeal metastasis。 Pulmonary lymphatic involvement leads to pulmonary dysfunction and requires active treatment, including the use of oxygen。 The investigator considered that the patient was not suitable for in this study, with any other situation.