Abstract: Objective: To analyze the related factors of the dental caries of 3-5-year-old children in Baotou. Methods: Four hundred and ninety-six 3-5-year-old children were randomly selected from 10 kindergartens in Baotou. 326 children who had caries were set as the case group and 170 children without caries as the control group by oral professional medical examination. 25 factors related to dental caries were investigated and recorded in two groups such as age, gender, daily snack times and daily brushing times, and so on. Then the related factors were analyzed with logistic multiple regression. Results: After excluding other factors involved in the model, per increase of daily snack time promoted the occurrence of dental caries 1.249 fold (OR was 1.249 and the 95% confidence interval did not contain 1, P<0.05). Weaning more than 1-year-old promoted the occurrence of dental caries 2.812 fold (OR was 2.812 and the 95% confidence interval did not contain 1, P<0.01). Risks to promote caries of not containing the bottle to sleep, not eating bedtime snack, and not drinking carbonated drinks were 0.194, 0.302, and 0.031 times of doing the above things (OR respectively was 0.194, 0.302, and 0.031, and all their 95% confidence interval did not contain 1, P<0.01). Conclusion: Increasing snack times and more than 1-year-old weaning are the dental caries risk factors of 3-5-year-old children of Baotou, while not containing the bottle to sleep, not eating bedtime snack, and not drinking carbonated drinks are the protective factors.