Objective   To study the knowledge of pr eschool children about oral health in Chong qing.

  Methods   From September to October in 2001 oral health course were given to 484 preschool children in 6 primary schools in Chongqing, which amounted to 8-class hours and lasted 2 months, and questionnaire investigation was taken before and after giving lessons.

  Results   The corr ect rate which the children answered the investigation increased from 61.92% before giving lesons to 90.19% after giving lessons.The correct rate remarkably improved.

  Conclusion   Giving oral health education and publicizing teeth disease prevention know ledge to preschool children canex tend preventing teeth disease from hospitals to schools.It was great meaningful to train the good oral hygienic habits, establish correct concept about how to prevent teeth diseases for raising children oral health level.