Objective  To examine the prevalence of dental caries and its influencing factors among primary school students in Liaoyuan city of Jilin province.

  Methods  An onsite self-administered questionnaire survey and oral examination were conducted among 2 230 pupils of grade 4 – 6 recruited with stratified random cluster sampling from 8 primary schools in 4 districts/counties of Liaoyuan city, Jilin province during 2021. Multivariate logistic regression analysis was adopted to explore main influencing factors of dental caries for the pupils.

  Results  Of the 2 071 participants (92.9% of all pupils recruited) with complete information, 1 413 (68.2%) were diagnosed with dental caries. The results of multivariate logistic analysis results showed that living in urban area (odds ratio OR = 4.511, 95% confidence interval 95%CI: 3 .564 – 5.711), studying in the lower grade compared to in the grade 6 (OR_{grade 4} = 1.916, 95%CI: 1.496 – 2.455; OR_{grade 5} = 3.446, 95%CI : 2.653 – 4.478), with overweight or obesity (OR = 1.757, 95%CI: 1.434 – 2.154), not using fluoride toothpaste (OR = 1.324, 95%CI : 1.004 – 1.746) were significant influencing factors of dental caries among the pupils.

  Conclusion  The prevalence of dental caries is high among primary students in Liaoyuan city of Jilin province, suggesting that to control the prevalence, comprehensive intervention strategies should be developed for main influencing factors of dental caries among the pupils .