Objective: To evaluate the changes of oral health status and oral health behavior among 12 year old children in Hainan province during 2005-2015, to provide basis for child oral disease prevention. Methods: Through the third and fourth national oral health epidemiology survey, changes in dental caries prevalence rate, dietary habit, oral health behavior, medical care in 12 year old chirdren were analyzed. Results: The percentage of dental caries in permanent, gingival blleeding, dental calculus of 12 year old chirdren in 2005 was 49.9%, 63.2%, 31.5% respectively, which 57.0%, 46.8%, 39.5% respectively in 2015( χ 2=6.78, 36.78, 9.45, P<0.05). The percentage of sugary snacks,drink and milk consumption every day in 2005 was 31.0%, 13.1%, 21.8% respectively, which increased to 40.3%, 27.5%, 30.8% in 2015(χ2=11.53, 38.76, 12.73, P<0.05). 49.3% children had a toothache in 2005, which increased 58.8% in 2015(χ2=23.43, P<0.05). Conclusion The prevalence of dental caries in permanent teeth of 12 year old children in Hainan was high, while eating habits was poor and oral health behavior was showed significant improvement. Oral health education for 12 year old should be strengthened.