Objective: To investigate the distribution profiles of the ABO blood group in gastric cancer patients and their relations with the occurrence of gastric cancer. Methods: The clinicopathologic data of 1 744 gastric cancer patients treated in Cancer Hospital affiliated to Harbin Medical University during 2010 to 2011 were retrospectively analyzed. The difference of distribution patterns of ABO blood types between gastric cancer patients and healthy population (496 447 cases) was compared, and the relations of blood types with clinicopathologic features of gastric cancer patients were determined. Results: Of the 1 744 gastric cancer patients, 554 cases (31.77%) were A blood type, 524 cases (30.05%) were B blood type, 468 cases (26.83%) were O blood type, and 198 cases (11.35%) were AB blood type, respectively. The distribution of ABO blood types in gastric cancer patients was statistically different to that in healthy population (χ2=38.384, P=0.000); the risk of gastric cancer in cases with A blood type was higher than in non-A individuals (OR=1.174, 95% CI=1.061–1.299), in cases with AB blood type was higher than that in non-AB individuals (OR=1.282, 95% CI=1.106–1.487), while in those with O blood type was lower than that in non-O individuals (OR=0.738, 95% CI=0.664–0.821). There was significant difference in tumor location between patients with O and B blood type (P<0.05), lymph node metastasis in patients with A blood type was higher than that in those with B blood type (72.77% vs. 65.57%, P<0.05), and distant metastasis of in patients with blood type A or O was higher than that in those with blood type AB (16.02% vs. 9.14%; 15.25% vs. 9.14%, both P<0.05). Conclusion: The distribution of ABO blood types in gastric cancer patients is different from that in healthy population. The risk of gastric cancer may increase in individuals with A or AB blood type, but decrease in those with O blood type, and blood types might be one of the risk factors for gastric cancer, and also be associated with the biological behavior of gastric cancer.