The purpose of this study is to find out whether treatment with metronomic capecitabine will improve the survival of gastric cancer patients with stage III who had received standard treatment.

Inclusion Criteria:

1. Lower age limit of research subjects 18 years old and upper age limit of 80 years old.
2. Be proven to be primary adenocarcinoma of gastric cancer and staged III by pathological evidences
3. R0 gastrectomy with D2 lymphadenectomy
4. ECOG (ECOG score standard) performance status of 0 or 1 and expected to survive more than 6 months
5. No contraindications, including normal peripheral blood routine, liver and kidney function and electrocardiogram （WBC≥3.5 x 109 /L, NEU≥1.2 x 109 /L,PLT≥90 x 109 /L and HGB≥80g/L).

Exclusion Criteria:

1. History of chemotherapy, radiotherapy, immunotherapy or target therapy
2. Multiple primary tumors
3. Suffering from other serious diseases, including cardiovascular, respiratory, kidney, or liver disease, complicated by poorly controlled hypertension, diabetes, mental disorders or diseases
4. Unavailable for R0 resection and D2 lymph node dissection.
5. Patients with stage IV gastric cancer