Objectives: To determine the level of bowledge, attitude, practice for dental and oral health care of Mong ethnic primary schools children in Yen Bai provice. Methods: Cross-sectional study with interview 1370 Mong ethnic school children in 04 primary schools: Ban Cong, Xa Ho (Tram Tau district).Nam Co, Pung Luong (Mu Cang Chai district),. Results: The level of good knowledge in preventing dental and oral diseases of Mong ethnic school children is 38,10 percent, medium is 42,26 percent, poor is 19,64 percent. The level of good attitude in preventing dental and oral diseases of Mong school children is 52,48 percent, medium is 34,08 percent, poor is 13,44 percent. The level of good practice in preventing dental and oral diseases of Mong ethnic school children is 28,62 percent, medium is 37,88 percent, poor is 33,50 percent. Conclusions: The level of knowledge, attitude, practice of preventing dental and oral diseases in Mong ethnic primary school children is low. The Mong ethnic school children in here is not interested in, education supporting, communication on practice dental and oral hygiene therefore it was affected to their health. the authors have some health and educaton programs in oral health to enhance the knowledge, attitude and practice on prevention dental and oral disease for primary school children.