Abstract: Background. Chaoshan is the only littoral among the six high-risk areas of esophageal carcinoma (EC) in China and the relatively isolatal society for the inconvenient transport gives an opportunity to study the genetics of carcinoma of esophagus and cardia. Some reports had suggested that ABO blood groups were associated with tumors, but their relation remained controversial.Methods: The data of age, sex, ABO blood type and X-ray or pathological diagnosis of the patients with carcinoma of esophagus or cardia were collected from The tumor hospital, First affiliated hospital, Second affiliated hospital of Shantou University Medical College; the Center hospital of Shantou and the Center hospital of Jieyang. In this study, 6 685 patients with EC and 2 955 patients with cardiac cancer(CC) in Chaoshan district were retrospectively assessed the association with ABO blood groups.Results: The distribution of ABO blood groups in patients with EC or CC was similar to the normal local population in Chaoshan. However, there was 2.3% excess of blood group B in male patients with CC and 4.7% excess in the patients with carcinoma in the upper third esophagus, compared with the corresponding controls. The relative risk B:O was 1.1415 (P<0.05) and 1.2696 (P<0.05), respectively No relationship between ABO blood groups and tumor differentiation was found.Conclusion: ABO blood group B was associated with the incidence of CC in male individuals and carcinoma in the upper third esophagus. The distribution of ABO blood groups varied in the different geographical and ethnic groups, as a result, proper controls were very important for such study.