There were limited data for nab-paclitaxel and S-1 in pancreatic cancer. To explore the efficacy and safety of neoadjuvant nab-paclitaxel combined with S-1 in patients with resectable pancreatic cancer (stage II and partial stage III defined according to the National Comprehensive Cancer Network definitions ), we designed this study. This study was a single-arm single center prospective phase II clinical study. A total of 72 subjects who meet the criteria will receive neoadjuvant chemotherapy of nab-paclitaxel and S-1 prior to pancreatectomy. Response was reported according to the Response Evaluation Criteria in Solid Tumors guidelines (RECIST, version 1.1) .The primary endpoint is objective response rate. The secondary endpoints include R0/R1 resection rate, disease free survival, overall survival and safety.

Inclusion Criteria:

1. Signed informed-consent form;
2. Treatment-naive PDAC with histological or cytological diagnosis;
3. Resectable pancreatic cancer stage II and partial stage III defined according to the National Comprehensive Cancer Network definitions;
4. Age≥18 years old and ≤70 years old;
5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1;
6. BMI≥18.5 and NRS2002score<3;
7. Expected survival over 3 months;
8. Spared organ function satisfying the following laboratory data:leucocyte≥3.0x109/L,neutrophils≥1.5x109/L, hemoglobin≥ 9g/dL, platelets ≥100x109/L, total bilirubin ≤ 1.5 ULN; AST and ALT≤ 2.5 ULN; serum creatinine≤1.5ULN; PT and INR≤ 2.5 ULN;

Exclusion Criteria:

1. Severe Impaired organ functions;
2. Patients who had surgeries, chemotherapy or other treatments before inclusion;
3. Pregnant women or lactating women;
4. Ineligible by the discretion of the investigator.