Objective To evaluate the internal exposure level of antibiotics in children and analyze its influencing factors.Methods Questionnaires were disseminated and urine samples were collected in June 2022 from kindergarteners and children enrolled in primary schools in a city in Jiangsu Province. The presence of 41 antibiotics was detected in urine using ultra-performance liquid chromatography and tandem mass spectrometry. Chi-square tests and rank-sum tests were performed to test the detection frequencies and concentrations of urinary antibiotics. Logistic regression models were established to identify the independent variables associated with the detection frequencies and concentrations of urinary antibiotics.Results A total of 295 children aged 3-8 from Jiangsu Province were included in this study. The detection frequencies of the antibiotics ranged from 0 to 48.1%， with sulfameter （48.1%） having the highest frequency， followed by sulfadiazine （38.3%） and erythromycin （38.3%）. The 95^th percentile concentrations of the antibiotics ranged from 0 to 23.7 ng/mL， with amoxicillin （23.7 ng/mL） having the highest concentration， followed by azithromycin （6.3 ng/mL） and sulfadiazine （3.5 ng/mL）. The results of Logistic regression analysis showed that age， residence， source of drinking water， and freshwater fish and shrimp consumption frequency were identified as independent influencing factors for specific antibiotic exposure.Conclusion Different antibiotics were detected in the urine of children in Jiangsu Province. Intervention measures should be adopted to reduce the exposure of children to antibiotics associated with high detection frequencies and concentrations.