The purpose of this study is to assess the difference of safety and efficacy about Capecitabine and S-1 for treatment of patients with low-risk of recurrence after BTC surgery.

Patients received curative BTC surgery will be informed about the study. After being informed about the study and potential risks, all patients giving written informed consent will undergo a 1-week screening period to determine eligibility for study entry. At week 0, patients who meet the eligibility requirements will be observed for recurrence of BTC.

Inclusion Criteria:

1. Male or female, age> 18 years old, and <75 years old.
2. Diagnosis is gallbladder cancer or biliary adenocarcinoma via pathological histology.
3. Patients have received curative surgery of gallbladder cancer or bile duct cancer, and postoperative pathology has confirmed R0 / R1 resection.
4. Ability to comply with the study protocol, in the investigator's judgment.
5. No tumor recurrence before the start of chemotherapy.
6. No fluorouracil drugs were used in the past six months.
7. The main organ function is good, that is, within 14 days before the start of medication, laboratory inspection confirmed that there is sufficient bone marrow function, liver function, renal function, heart function: hemoglobin ≥90g / L; neutral granulocyte count ≥1.5 × 109 / L; platelet ≥ 70 × 109 / L; alt, AST ≤ 3 × ULN (normal value upper limit); total bilirubin ≤ 2.5 × ULN (normal value upper limit)); serum creatinine <1.5 × ULN (normal value upper limit); Serum albumin ≥ 30g / L; coagulation function: PT extended <2s.
8. ECOG score <2.
9. Signed Informed Consent Form.
10. Male and female subjects with potential fertility must agree to adopt high-efficiency contraceptive methods during the study of at least 3 months after receiving the last treatment.

Exclusion Criteria:

1. First chemotherapy start time > 16 postoperatively weeks.
2. Patients with other tumors, or patients with recurrence before chemotherapy;
3. History of allergic with study drugs;
4. History of organ transplantation requires immunosuppressive treatment;
5. Pregnancy or lactation women;
6. Accept the following system treatment within 4 weeks before the start of treatment: cytotoxic treatment, signal conduction inhibitors, immunotherapy, hormone therapy.
7. Participate in other clinical trials within 3 months;
8. Abnormality of the peripheral nervous system (> NCI CTC 1), clinically significant mental abnormalities, have a history of abnormal history of the central nervous system;
9. Electrocardiogram abnormal or clinically obvious heart disease, such as: congestive heart failure, symptomatic coronary heart disease, arrhythmia, clinical manifestations of heart disease, or epasus in the past 12 months; severe infection (> GRADE 2 National Cancer Institute [NCI] -Common Terminology Criteria for AdverSe Events [CTCAE] Version 3.0), sepsis, severe metabolism or diabetes; Digestive ulcer activity period requires treatment, absorption disabilities, diarrhea, intestinal obstruction , Destroyer of the upper deactivated tract integrity;
10. History of HIV infection;
11. Anti-viral treatment cannot be controlled or chronic hepatitis C;
12. Renal failure requires blood or peritoneal dialysis;
13. There are some other serious or unstable diseases or medical, social, sychological states, can endanger the safety of the subject and / or his / her to study the compliance or can prevent patients to participate in clinical research or The assessment of the research results;
14. Refused follow-up in accordance with the requirements set by this research program, as well as refused to sign informed consent.
15. Other factors that may affect patient income and assessment results;

Patients have received curative surgery of pathological diagnosed gallbladder cancer or bile duct cancer.