Inclusion Criteria:

- Age: 18-75 years old female.

- ECOG status: 0-2.

- Life expectancy of ≥ 3 months.

- Histologic or cytologic diagnosis of breast cancer.

- Progression after receiving one standard prior chemotherapy regimen for recurrent or
metastatic lesion except an endocrine regimen.

- At least one measurable lesion of >=2 cm (>=1 cm on spiral CT scan)according to
RECIST (v1.1).

- Adequate organ functions:

- Hematopoietic: Hemoglobin ≥90g/L, Absolute neutrophil count ≥1.5×10^9/L,
Platelet count ≥80×10^9/L.

- Biochemistry: TBil ≤1.5 times upper limit of normal (ULN), AST and ALT ≤2.5×
ULN(≤5x ULN if due to liver metastases), Creatinine ≤1.0×ULN and Creatinine
clearance >50 ml/min.

- Women with children potential must have negative pregnancy tests 7 days prior to
enrollment and be willing to practice acceptable methods of birth control during the
study and 8 weeks after last drug administered.

- Ability to take oral medication .

- Signed informed consent.

Exclusion Criteria:

- Pregnancy or lactation or no effective contraception in fertile patients.

- Prior treatment with 5-FU or drugs of same class(excluding patients that relapsed
more than one year after adjuvant therapy).

- Less than 4 weeks since prior investigational agents.

- conditions impacting oral drug taking or absorption (e.g. inability to swallow,
gastrointestinal resection, chronic diarrhea, intestinal obstruction).

- Organ invasion with rapid progression(e.g. lesions exceeding half of Liver or Lung).

- CNS or psychiatric disorders.

- Allergic to 5-FU.

- Only with bone metastases and no measurable lesions.

- Clinically significant heart diseases (e.g.congestive heart failure, ventricular
arrhythmia, myocardial infarction) before enrollment.

- Serious peptic ulcer disease or digestive disorders.

- Bone marrow (Hemoglobin <90g/dl, ANC <1.5×10^9/L, Platelet count <75×10^9/L).

- Renal function disorder (Creatinine >1.0×ULN).

- Liver function disorder (TBil >1.5×ULN).

- Uncontrolled brain metastases.

- Noncompliance with the study protocol.