Objective: To evaluate ten year changes in deciduous teeth health and oral health behavior aged 5 year old children in Hainan province (during the year of 2005-2015), to provide basis for oral health promotion among 5 year old children in Hainan province. Methods: Through the comparison and analysis of the third and the fourth national oral health epidemiology survey,changes of dental caries prevalence rate, dietary habit, oral health behavior, and health seeking behavior were analyzed. Results: The prevalence of dental caries in 2005 was 76.1%, 2015 was 82.3% which had significant difference(χ2=6.23，P<0.05), the percentage of consuming sugary food and sweet drinks every day in 2005 was 13.4% and 6.1%, which increased to 30.0% and 7.4% respectively in 2015. The percentage of drinking milk and yoghurt with sugar was 47.6%, which decreased 36.5% in 2015 (χ2=12.76，P<0.05), the percentage of consuming sugary food and sweet drinks before going to bed in 2005 was17.8%, which decreased to 13.3% in 2015 (χ2=32.27，P<0.05). The percentage of brushing the teeth two or more times a day was 16.9%, which increased to 24.2% in 2015(χ2=20.50，P<0.05). The percentage of using fluoridated toothpaste decreased from 31.7% (2005) to 7.4% (2015) (χ2=229.13，P<0.05). No need to treatment for baby teeth and afraid of pain among children were the main reason for no health-seeking among parents which children of dental health problems,which deffered significantly between 2005 and 2015(χ2=6.05，9.34，P<0.05). Conclusion Children’s oral health behavior improved, while eating habits fluoridated toothpaste usage and health seeking behavior remain poor.Health education on child oral health should be strengthened.