Although FOLFIRINOX regimen was recently presented to be effective for metastatic pancreatic cancer in selected patients who have good physical condition, there is still insufficient evidence on this regimen in treating patients with metastatic pancreatic cancer in China. Since for many tumors, different races may show different responses to the same regimen, we design this open, multicenter phase Ⅱ study to evaluate the the efficacy and safety of mFOLFIRINOX as first-line treatment for metastatic pancreatic cancer in China.