A Study of Raltitrexed Plus Docetaxel Versus Docetaxel as Second-line Chemotherapy in Subjects With Gastric Cancer

Inclusion Criteria: 1. Signed informed consent form 2. Performance Status- Eastern Cooperative Oncology Group (ECOG) 0-2; 3. Histologically or cytologically confirmed gastric cancer; 4. The first-line chemotherapy failure (required containing 5-fluorouracil) 5. At least have one measurable disease(according to RECIST, Response Evaluation Criteria in Solid Tumors ) 6. Life expectancy of at least 3 months; Exclusion Criteria: 1. Received any prior treatment including Raltitrexed; 2. Active or uncontrolled infection; 3. Concurrent treatment with an investigational agent or participation in another therapeutic clinical trial; 4. Pregnant or lactating women.