Abstract: Objective To explore the biomechanical mechanism of non-erosive reflux disease(NERD). Methods From October 4,2014 to September 30,2015，17 NERD patients and 17 healthy controls were recruited from the outpatients department of China-Japan Friendship Hospital.The cross-sectional area(CSA)、intra-balloon pressure (IBP)and compliance(（Δv/Δp）of each were measured by endoscopy in combination with EndoFlip. Results With the increase of balloon volume,the compliance of gastroesophageal junction in NERD group was significantly higher than that of control group（p<0.01） while the cross sectional area and intra-balloon pressure were similar.Conclusion Increased compliance of the gastroesophageal junction might be a factor in the pathogenesis of non-erosive reflux disease.

Key words: Key words: non-erosive reflux disease, compliance, gastroesophageal junction