Objective To compare the applicability of the 7th and 6th editions of the UICC-AJCC esophageal cancer TNM staging systems for adenocarcinoma of esophagogastric junction (EGJ).Methods During June 2007 through December 2010,199 patients with EGJ adenocarcinoma(Siewert type Ⅱ) underwent R0-intent resection in our hospital.Their clinicopatholigical and survival data were retrospectively analyzed with Kaplan-Meier and Cox regression models.They were restaged according to the 7th and 6th UICC/AJCC TNM staging systems for esophageal cancer,respectively.Then the Akaike information criterion(AIC) was used for measuring goodness of fit of both staging systems.Results Among 199 patients,there were 162 males and 37 females.Univariate analysis indicated that age(P =0.009),surgical approach(P =0.002),cell differentiation (P =0.030),preoperative co-morbidity (P =0.026),depth of tumor invasion (P ＜ 0.000) and number of metastatic lymph nodes(P ＜ 0.000) were significant influencing factors on overall survival.Multivariate analysis demonstrated that the independent prognostic factors for EGJ adenocarcinoma were age,T stage,N stage and preoperative co-morbidity according to the 6th edition of esophageal cancer TNM staging system,and only T stage,N stage and preoperative co-morbidity according to the 7th edition of esophageal cancer TNM staging system.The AIC value was 961.4 for the 7th edition of esophageal cancer staging system and 972.4 for the 6th edition.Conclusion The 7th edition of UICC/AJCC esophageal cancer TNM classification is su perior to its 6th edition of esophageal cancer staging system for EGJ adenocarcinoma.