AIM To study the relationship between ABO blood groups and carcinoma of esophagus and cardia in Chaoshan inhebitants of China, which is a unique Littoral high-risk area of esophageal carcinoma in China. The poor communication and transportation in the psst has made Cheoshan a relatively closed area and kept its culture and costure of old China thousend years ago.``METHODS Data on age, sex, ABO blood type and X-rayor psthological diagnose of the pstients with carcinoma of esophagus or cardia were collected from the Tumor Hospital. First Affiliated Hospital, Second Affiliated Hospital of Shantou University Medical College; and the Central Hospital of Shantou and the Central Hospital of Jieyang. A total of 6685 pstients with esophageal carcinoma (EC) and 2 955 patients with cardiac cancer (CC) in Chaoshen district were retrospectively assessed for their association with ABO blood groups.``RESULTS The distribution of ABO blood groups in patients with EC or CC was similar to the norrnal local population in Chaoshen. However, blood group B in male patients with CC and in the pstients with carcinoma in the upper third esophagus was 2.3% and 4.7% higher than the corresponding controls. The relative risk B: O was 1. 1415 (P＜0.05)and 1 .2696 (P＜0.05), respectively. No relationship was found between ABO blood groups and tumor differentiation.``CONCLTUSION ABO blood group B is associated with the incidence of CC in male individuals and carcinona in the upper third esophagus. The distribution of ABO blood groups varies in the different geographical and ethnic groups. As a result, proper controls are very important for such studies.``