Objective To evaluate the internal exposure level of antibiotics in children and analyze its influencing factors. Methods Questionnaires and urine samples were collected among children recruited from kindergartens and primary schools in one city of Jiangsu province in June 2022. Forty-one antibiotics were tested in urine by ultra-performance liquid chromatography and tandem mass spectrometry. Chi-square tests and rank-sum tests were used 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 295 children aged 3-8 from Jiangsu province were included in this study. The detection frequencies of individual antibiotics ranged from 0 to 48.1%, among which sulfameter (48.1%) was the highest, followed by sulfadiazine (38.3%) and erythromycin (38.3%) . The 95th percentile concentrations of individual antibiotics ranged from 0 to 23.7 ng/mL, among which amoxicillin (23.7 ng/mL) was the highest, followed by azithromycin (6.3 ng/mL) and sulfadiazine (3.5 ng/mL). Age, residence, source of drinking water, freshwater fish and shrimp consumption frequency were independent influencing factors for specific antibiotics exposure. Conclusions Various antibiotics were detected in the urine of children in Jiangsu province. Intervention measures should be taken to reduce children's exposure to antibiotics with high detection frequencies and concentrations.