Abstract: Objective To explore the risk factors associated with gastroesophageal reflux in oldest old patients with long-term nasal feeding. Methods Sixty-four elderly patients who underwent nasogastric tube enteral nutrition treatment were chosen in Chinese PLA General Hospital from April 2017 to October 2017. We collected 1-3 ml saliva from patients at 30 minutes before and after lunch and dinner. The concentration of pepsinogen Ⅰ (PGⅠ) in saliva was detected by latex enhanced immunoturbidimetry and the result of gastroesophageal reflux (GER) was identified as positive when PGⅠwas> 2.5μg/L at least at one time. Patients' gastric residuals volume (GRV) was measured with refractometry. The relationship between GER and GRV and other factors were analyzed by univariate analysis and logistic regression analysis. Results Thirty-four patients (53%) of the enrolled patients were GER positive.There was no correlation between GRV and GER (P> 0.05). Multivariate analysis showed that age, diabetes and nasal feeding method were risk factors for GER, with OR values of 4.173, 6.242, and 5.509, respectively. Conclusion Oldest old patients with long-term nasal feeding should be fed by slow drip nasal feeding method. For patients with history of diabetes, we should pay more attention to the occurrence of GER. There is no correlation between the occurrence of GER and GRV.