Objective:To investigate and analyze the oral health knowledge and behavior of 12-year-old schoolchildren in Chongqing.Methods:Based on"The Guidline for the Third National Oral Health Survey"

a stratified equal-sized randomly sampling design was applied to obtain 359 objects aged at 12 years old who were responded to questionnaire on oral health knowledge and behavior.Results:Above 70% children had positive attitudes towards some oral health knowledges

while only less than 50% children could grasp knowledge about gingival bleeding.Most children could not take correct measure about gingival bleeding and toothache

and only brushed teeth once a day.Some children did not insist in brushing teeth everyday.The children living in the urban show higher percentages of positive attitudes to some basic oral health knowledge and toothbrushing than those living in the rural(P<0.05).Conclusion:Among 12-year-old children in Chongqing

some oral health knowledges are poor

and oral health behavior is not good

and there is difference between the urban and the rural.In the following time

attention should be paid to oral heath education with the utilization of school for the oral health care of chongqing.