This is a randomized multicenter controlled study of oxaliplatin, leucovorin calcium , plus 5-fluorouracil (FOLFOX) compared with S-1 plus oxaliplatin (SOX) as perioperative chemotherapy for advanced gastric cancer.

Hypothesis: SOX is not inferior to FOLFOX as perioperative chemotherapy for advanced gastric cancer.

Inclusion Criteria:

• Histologically confirmed gastric adenocarcinoma,diagnosed as locally advanced gastric cancer and primary tumor invades or penetrates serosa
• Ambulatory males or females, aged 18-80 years old
• ECOG score 0-2
• Given informed consent
• Life expectancy more than 3 months
• Measurable lesion
• Normal cardiac, hepatic, renal, and bone marrow function(WBC:3.5×10^9/l~12×10^9/l;PLT:>100×109/l;Bil:<1.5 fold of upper limit value; ALT/AST:<2.5 fold of upper limit value;Ccr:>80ml/min;Cr:1.5mg/dl)

Exclusion Criteria:

• Prior stomach surgery
• Previous cytotoxic chemotherapy, radiotherapy, target therapy or immunotherapy for any tumor
• History of another malignancy except cured basal cell carcinoma of skin and cured carcinoma in-situ of uterine cervix
• distant metastasis(such as No.16 and No.13 lymphnode,liver, lung,brain,bones or peritoneal metastasis)
• Severe bleeding
• Bowel obstruction, ileus or complete pyloric obstruction
• Serious uncontrolled concomitant disease
• History of myocardial infarction in 6 months
• Woman with on-going pregnancy or breast-feeding, or contemplating pregnancy
• Systemic treatment with corticosteroid
• Patients judged inappropriate for the trial by the physicians