Abstract:  In recent years, the incidence of gastric cancer has been decreasing year by year in the world, but the incidence of adenocarcinoma of esophagogastric junction (AEG) has shown a significant upward trend, especially in western countries such as Europe and America. The prognosis of AEG is poor, therefore, it is extremely necessary to establish AEG′s best diagnosis and treatment strategies to improve the long-term outcome of AEG. Nowadays, the most commonly used AEG classification is the Siewert classification proposed by German scholars in 1987, which is based on the anatomical features of the esophagogastric junction. It provides guidance for the choice of surgical methods. Compared with European and American countries, Siewert type Ⅱ or type Ⅲ are more common in Asian countries, and are mainly treated as the proximal gastric cancer. Compared with gastric tumors in other areas, AEG has obvious differences and specialities in anatomy, physiology and pathology, and there is still much controversy in the field of surgical and comprehensive treatment.