Objective：To detect the expression of sine oculis homeobox homolog-6 （SIX6） in gastric adenocarcinoma，and analyze its value in judging prognosis. Methods：A total of 79 cases of gastric adenocarcinoma tissue were collected as the observation group，while another 79 cases of normal gastric mucosa tissue with a distance > 3 cm to tumor boundary were collected as the control group. All cases were took the fresh tissue and conducted the paraffin-embedded tissue. Immunohistochemisty was used to detect the expres－sion of SIX6 protein in paraffin-embedded tissue，Western blot was used to detect the semiquantative expression of SIX6 protein in the fresh tissue，survival analysis was used to observe the relationship between SIX6 and survival time，and real-time fluorescence quantitative PCR was used to detect the expression of SIX6 mRNA in 15 cases gastric adenocarcinom tissue and 15 cases of normal gastric mucosa tissue. Results：Positive rate of SIX6 expression in two groups had statistically significant differences in two groups （53.2% vs. 6.3%， χ2=41.461，P=0.000）. In the experimental group，expression of SIX6 was correlated with tumors' maximum diameter（33.3% vs. 69.8%， χ2=10.446，P=0.001），infiltrated depth（21.9% vs. 74.5%， χ2=21.149，P=0.000），vascular thrombus（44.0% vs. 69.0%， χ2=4.594，P=0.032），lymph node metastasis（31.8% vs. 80.0%， χ2=18.175，P=0.000） and inflammatory cell infiltration（25.9% vs. 67.3%， χ2=12.223，P=0.000），but not with gender，age and cell differentiation（P>0.05）. Survival analysis results showed that expression of SIX6 was correlated with survival time（ χ2=4.243，P=0.040）. Semiquantative expression of SIX6 protein（1.21±0.06 vs. 0.92±0.04，t=3.85，P=0.000） and mRNA（1.30±0.18 vs. 0.82±0.11，t=2.25，P=0.033） in the experimental group were higher than those in the control group. Conclusion：Higher expressions of SIX6 protein and mRNA in the experimental group are significantly increased in the gastric adenocarcinoma tissue，which plays a certain adjusting role in the formation and development of tu－mor. SIX6 is correlated with the prognosis of gastric adenocarci－noma.