Objective To investigate the prevalence and risk factors of dental caries and its related influencing factors in 12-year-old children in Yangpu District， Shanghai， and to provide relevant data support for the formulation of oral health policies and measures for children.

Methods In 2021， 839 12-year-old children were randomly selected from five ordinary junior high schools in Yangpu District. The investigation included an oral health examination and a questionnaire survey on factors related to dental caries. Logistic regression analysis was used to analyze the influencing factors of dental caries.

Results Among the 839 participants， data from 830 were included. Among them， 426 were male （51.3%） and 404 were female （48.7%）. Of the 830 children， 203 had dental caries， resulting in a caries prevalence of 24.46%， a caries supplemental filling ratio of 32.6%， and a DMFT of 0.63. Multivariate logistic regression analysis revealed that a mother’s education level of college or above （OR=0.849，95% CI： 0.732‒0.984）， brushing teeth twice a day （OR=0.827，95%CI： 0.703‒0.973）， and the caregiver brushing teeth twice a day （OR=0.843， 95%CI： 0.726‒0.983） were effective factors in reducing the caries rate. Factors associated with childhood dental caries included consuming sweets ≥1 time per day （OR=1.397，95%CI： 1.197‒1.342） and female gender （OR=1.482，95%CI： 1.347‒1.671）.

Conclusion The prevalence of dental caries among 12-year-old children in Yangpu District is 24.46%. Gender， maternal education， the frequency of children's toothbrushing， the frequency of sweet consumption， and the caregiver’s toothbrushing frequency are the main factors affecting the prevalence of dental caries in children.