Abstract: Objective To detect the expressions of Cyclooxygenase 2(COX-2) and Melanoma-associated antigen 1(MAGE-1) in resected tumor tissues of gastric adenocarcinoma patients and analyze their relationship and the impact on the 5 year survival of the patients. Methods Immunohistochemistry was used to analyze the COX-2 and MAGE-1 expressions in 67 tumor samples resected from gastric adenocarcinoma patients. Statistical analysis was conducted by chi-square test. Results COX-2 was over-expressed in 55.2% of the patients, MAGE-1 was over-expressed in 46.3% of the patients. Over expression of COX-2 was a factor to reduce the 5-year survival rate while the over expression of MAGE-1 was not an influence factor. There was no correlation between COX-2 expression and MAGE-1expression (P=0.156). Conclusion Both COX-2 and MAGE-1were over-expressed in gastric adenocarcinoma tissues, COX-2 over expression was significantly related with low 5-year survival rate.