Background: Caries can harm children’s physical health, mental health, and overall development. To understand the factors that influence children’s risk of dental caries and the status of dental caries among children in Beijing, China, aged 3–5 years and to determine parents' KAP regarding their children’s oral health.Methods: The research subjects were parents who accompanied their children to a hospital for dental examination, and parents who attended community-based oral-health consultations. Data were collected through a questionnaire survey. The data were statistically analyzed using SPSS software.Results: Overall, 41.4% of the children had dental caries. The parents had high demand for dental-caries-related knowledge, and were willing to receive such knowledge from a variety of sources. Logistic regression models showed that factors that impact children’s caries were the mother’s educational background, whether parents regularly acquire oral-health knowledge, and whether children have a dental examination each year.Conclusion: In Beijing, approximately half of the children aged 3–5 years have dental caries. Parents have good knowledge and attitudes regarding their children’s oral health, but their associated actions are insufficient. Therefore, it is necessary to provide parents with assistance regarding managing children’s oral health.