• 1\) Subjects fully understand the purpose, nature, method and possible adverse reactions of the study, volunteer as subjects, and sign informed consent prior to the commencement of any study procedure;

• 2\) Male and female, ages 18-75 years both inclusive;

• 3\) Subjects with breast cancer confirmed by histopathology and/or cytology who meet one of the following conditions: ①Metastatic breast cancer, after failure of combination chemotherapy for metastatic disease or relapse within 6 months of adjuvant chemotherapy. Prior therapy should have included an anthracycline unless clinically contraindicated; ②This treatment criteria (NCCN guidelines and CSCO guidelines - Breast cancer) is used to determine whether the subjects are suitable for paclitaxel for injection (albumin-bound) monotherapy. ③Subjects received standard treatment without conditions and were judged to benefit from injectable paclitaxel (albumin-binding) monotherapy;

• 4\) ECOG Score ≤ 2 points;

• 5\) The expecting life span ≥ 3months;

• 6\) The results of blood, liver and kidney function tests are within the following ranges: Absolute neutrophil counts (ANC) ≥ 1.5×10\^9/L Platelets (PLT) ≥ 100×10\^9/L Hemoglobin (Hb) ≥ 90 g/L Total bilirubin (TBIL) ≤ 1.5×ULN Alanine transaminase (ALT), Aspartate aminotransferase (AST)≤×ULN (for patients with liver metastasis, ≤ 5×ULN) Creatinine clearance (CrCL)≥ 60 mL/min

• 7\) The subject has no fertility plan (including sperm donation and egg donation) for at least 6 months from the signing of informed consent to the last dose and voluntarily takes non-drug effective contraceptive measures;

• 8\) Subjects can communicate well with the investigators, understand and comply with the requirements of the study.