The present study is intended to investigate the efficacy and safety of the patients with confirmed advanced pancreatic cancer after treating with the combination of paclitaxel liposome plus S-1.

Allocation: Non-randomized Endpoint Classification: Efficacy/ Safety Study Intervention Model: single arm Masking: Open Lable Primary Purpose: Treatment

Inclusion Criteria:

1. Age ≥18 years and ≤75 years;
2. the patients were confirmed as locally advanced or metastatic pancreatic cancer by histopathology;
3. At least one measurable objective lesion was identified based on the RECIST1.1 criteria;
4. Eastern Cooperative Oncology Group (ECOG) performance status 0-1;
5. The expected survival after surgery ≥3 months;
6. Adequate liver/kidney/bone marrow function： Absolute neutrophil count (ANC) ≥1.5×10^9/L; Hemoglobin (Hgb) ≥9g/dL; Platelets (PLT) ≥100×10^9/L; Total bilirubin (TBIL) ≤1.5×ULN; Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT]/ alanine aminotransferase (ALT) (serum glutamic pyruvate transaminase [SGPT]) ≤2.5×institutional upper limit of normal (ULN), or ≤5×ULN(hepatic metastases); Serum creatinine level is normal or creatinine clearance rate≥60 mL/min/1.73 m^2.
7. Subjects of child-bearing age must agree to take effective contraceptive measures during the study period; Serum or urine pregnancy tests must be negative for women of childbearing age 7 days before the start of chemotherapy、during the monthly treatment interval and after the last treatment;
8. Signed informed content obtained prior to treatment.

Exclusion Criteria:

1. Symptomatic ascites;
2. The target disease has cerebral metastasis;
3. Previously received palliative chemotherapy or other palliative systemic therapy for advanced/metastatic pancreatic cancer;
4. Previously received treatments based on paclitaxel liposomes or S-1, except for neoadjuvant therapy or adjuvant therapy (before and after R0/R1 excision), which was based on paclitaxel liposomes or S-1(the time of discontinuation of neoadjuvant/adjuvant chemotherapy before admission ≥6 months);
5. Received surgical treatment ≤4 weeks before admission;
6. Severe cancer-related cachexia and/or known weight loss >15% occurred within one month before admission;
7. The medical history and complications, which may affect patients' ability to participate in the study and their safety during the study, or interfere with explanation of the study results, for example: uncontrolled hypertension, cardiovascular and cerebrovascular diseases such as cerebrovascular accident (≤6 months from the start of the study), myocardial infarction (≤less than 6 months from the start of the study), unstable angina pectoris, heart failure (≥2 grades) (NYHA functional score), severe arrhythmia requiring medication, metabolic dysfunction, severe renal insufficiency;
8. Human immunodeficiency virus (HIV) or Hepatitis B Virus（HBV）、hepatitis C virus (HCV) positive with Liver dysfunction;
9. Combined with other malignant tumors excepted pancreatic cancer within the first 5 years of admission, excepted cured carcinoma in situ of cervix、basal cell carcinoma of the skin;
10. History of allergy or hypersensitivity to any therapeutic ingredient;
11. Patients with known active alcohol or drug abuse or dependence;
12. Pregnancy, or women who are currently trying to conceive, or who are likely to have children and do not use contraceptives, or breastfeeding women;
13. Participation in any trial drug treatment or another interventional clinical trial 30 days before screening period.