Objective:To investigate the factors related to gastroesophageal reflux disease (GERD) in children.Methods:Clinical data of 370 children who underwent 24h multi-channel impedance-pH monitoring (24h MII-pH) in Children′s Hospital Affiliated to Capital Institute of Pediatrics from January 2015 to December 2020 were enrolled in the study. The children were divided into GERD group ( n=202)and non-GERD group ( n=168) according to results of 24h MII-pH. The relationship of sex, age, body mass index (BMI), disease course, peripheral blood eosinophils count, IgE, Helicobacter pylori (Hp) infection, hiatus hernia of patients with GERD was analyzed by univariate and multivariate logistic regression analysis. Results:In GERD group 124 were males and 78 were females with a mean age of (6.4±4.1) years (2 months to 16.75 years), and in non-GERD group 82 were males and 86 were females with a mean age of (8.0±3.5) years (10 months to 15.17 years). Univariate logistic regression analysis showed that sex( OR=0.600,95% CI:0.396-0.908, P=0.016), age ( OR=0.537,95% CI:0.412-0.699, P<0.001)and hiatus hernia( OR=7.433,95% CI:2.567-21.520, P<0.001)were significantly associated with GERD of the children. Multivariate analysis showed that hiatus hernia ( OR=4.023,95% CI:1.298-12.470, P=0.016) was the independent risk factor, while male gender ( OR=0.567,95% CI:0.367-0.874, P=0.010) and younger age ( OR=0.613, 95%CI:0.459-0.819, P=0.001 ) were related factors of gastroesophageal reflux disease in children. Conclusion:Sex, age, and hiatal hernia are factors related to GERD in children.