Introduction: To survey the status caries and knowledge, attitude and practice of oral care of Secondary school students. Aim: To describe caries status and knowledge, attitude and practice of oral care in the age group of 12-15 students of junior high school in Bat Trang, Gia Lam, Hanoi, 2013. Methods: descriptive cross-sectional study on 361 high school students in Bat Trang, Gia Lam, Hanoi, 2013. Caries lesions were examined with the naked eye under criteria detection system and intensive evaluation teeth of WHO (1997). Infonnation about knowledge, attitudes, practices and a number of other factors were collected through questionnaires designed before. Results: Decay rate of the students was 59.8 percent: male (63.9 percent), female (55.1 percent). SMT index is 1.28 which is 1.03 in male students, female students is 1.58. 91.14 percent untreated tooth decay. Knowledge, attitude and practice of oral care students: 61.5 percent of understanding about the true causes of tooth decay, 64.3 percent of students know the correct methods of caries prevention. The attitude of the students for oral disease that doctors needed to treat was 80.9 percent, unpleasant but not requiring treatment was 5.5 percent, 8.6 percent heal, not interested is 5.5 percent. Practice good dental care: 14.7 percent did not brush your teeth, brush your teeth after eating everyday is 59.0 percent. Conclusion: Decay rate of 12-15 year-old students in relatively high (59.8 percent), knowledge, attitude and practice of oral care students poorly.