AIM: Gastroesophageal reflux disease (GERD) is a common disorder in the West population, but detailed populationbased data in China are limited. The aim of this study was to understand the epidemiology of symptomatic gastroesophageal reflux (SGER) in adults of Xi′an, a northwest city of China,and to explore the potential risk factors of GERD.METHODS: Symptoms suggestive of GERD, functional dyspepsia (FD), irritable bowel syndrome (IBS), upper respiratory diseases and some potential risk factors were investigated in a face-to-face manner in a region-stratified random samples of 2 789 residents aged 18-70 years in Xi′an by using a standardized questionnaire.METHODS: With a response rate of 91.8%, the prevalence of SGER was 16.98% (95% CI, 14.2-18.92) in Xi′an adults,and no gender-related difference was observed (P＜0.05).SGER was more common among subjects aged 30-70 years than in those aged 18-29 years (P＜0.01). The prevalence of SGER in rural, urban and suburban subjects was 21.07%,17.44% and 12.12%, respectively, and there was a significant difference between rural, urban and suburban regions (P＜0.05). Compared with subjects without SGER,the prevalence of symptoms suggestive of FD and IBS,pneumonia, asthma, bronchitis, laryngitis, pharyngitis,chronic cough, wheeze, globus sensation, oral ulcer and snore was significantly increased in subjects with SGER (P＜0.01). Heavy smoking (OR=5.76; CI, 3.70-6.67), heavy alcohol use (OR=2.85; CI, 1.67-4.49), peptic ulcer (OR=5.76;CI, 3.99-8.32), cerebral palsy (OR=3.97; CI, 1.97-8.00),abdominal operation (OR=2.69; CI, 1.75-4.13), obesity (OR=2.16; CI, 1.47-3.16), excessive food intake (OR=1.43;CI, 1.17-1.15), sweet food (OR=1.23; CI, 0.89-1.54),and consumption of coffee (OR=1.23; CI, 0.17-2.00) were independently associated with SGER. The episodes of GERD were commonly precipitated by dietary factors (66.05%),followed by body posture (26.54%), iii temper (23.72%),fatigue (22.32%) and stress (10.93%).CONCLUSION: GERD is common in Xi′an′s adult population with a mild or moderate degree. The etiology and pathogenesis of GERD are probably associated with FD, IBS, and some respiratory, laryngopharyngeal and odontostological diseases or symptoms. Some lifestyles, diseases and dietary factors are the risk factors of GERD.