Abstract: Objective To study oral health and its influencing factors in the children of different age.Methods Totally 1 260 children were divided into 3 groups according to their age and their oral health and the oral health-related knowledge and habit of the children were investigated.Results The prevalence rate of caries,gingivitis,and dental calulus was 52.8%,50.8%,and 55.4% for the children at ages of 3-6 years,36.6%,37.0%,and 38.9% for the children at ages of 7-10,and 25.1%,26.3%,and 25.5% at ages of 11-15,respectively,with significant differences among different age groups(P < 0.05 for all).For the children aged 3-6,7-10,and 11-15 years,the oral health-related knowledge rate was 32.4%,46.9%,and 59.6% and the rate of good oral hygienic hebit was 30.2%,45.8%,and 56.7%,respectively,with significant differences among different age groups(P < 0.5 for all).Linear correlation analysis showed that the prevalence rates of oral problem were significantly negatively correlated to the oral health-related konwledge rate and the rate of good oral hygienic habit,while the rate of good oral hygienic habit was significantly positively correlated to the oral health-related konwledge rate among the children.Conclusion There are relationships between the oral health and oral-related knowledge and oral hygiene.