Objective: To analyze the causes of the esophagogastric junction outlet obstruction (EGJOO) patients, to discuss the differences of the clinical manifestation and esophageal motility characteristics between the anatomic EGJOO (A-EGJOO) and functional EGJOO (F-EGJOO) subgroups, and to search the diagnostic values of the specific metrics for differentiating the subgroups of EGJOO patients. Methods: For the current retrospective study, all the patients who underwent the esophageal high resonance manometry test were retrospectively analyzed from Jan 2012 to Oct 2018 in Peking University Third Hospital. The EGJOO patients were enrolled in the following research. The clinical characteristics, such as symptoms and causes of the patients were studied. Then the patients were divided into two subgroups as A-EGJOO subgroup and F-EGJOO subgroup. The clinical symptoms and the main manometry metrics were compared between these two subgroups. The significant different metrics between the two groups were selected to draw receiver operating characteristic (ROC) curves and the diagnostic values were analyzed in differentiating the A-EGJOO and F-EGJOO subgroups. Results: The most common symptom of EGJOO was chest pain or chest discomfort (30.63%), then the dysphagia (29.73%), and acid regurgitation/heartburn (27.03%). Non-erosive reflux disease (36.04%) was the most popular cause for EGJOO, then the reflux esophagitis (17.12%). Besides the intra-EGJOO and extra-EGJOO lesions, the connective tissue disease (6.31%) and central nervous diseases (2.70%) were found to be the etiology of EGJOO. The causes of the rest 19 EGJOO were unknown. A-EGJOO patients presented significantly higher intra bolus pressure (IBP) than that of F-EGJOO [6.80 (5.20, 9.20) mmHg vs. 5.10 (3.10, 7.60) mmHg, P=0.016]. The area under curve of IBP was 0.637. When IBP≥5.15 mmHg, the sensitivity was 78.60% and specificity 50.70% to differentiate A- or F-EGJOO. Conclusion: Chest pain or chest discomfort was the most common symptom in EGJOO patients. Besides the intraluminal structural disorders, the extra-luminal causes were found in EGJOO patients. A-EGJOO presented higher IBP than that of F-EGJOO patients. The cutoff value of IBP to differentiate A-EGJOO from EGJOO was 5.15 mmHg with sensitivity 78.06% and specificity 50.70%. However for the low area under curve, the diagnostic value of IBP was limited.