Background and rationale: : Sok Pa Luang Primary School is one of the schools located in the big city and It is also a model school that lies in the promotion program and Prevention of childhood diseases as a program or planning in schools and Oral-dental health care program of the Faculty of Dentistry, University of Health has given health education to Sok Pra Luang Primary School, Si Sattanak District make aware of various behaviors which is the risk of tooth decay in children 10-12 years old this is an important issue and there is no survey yet. Since the school dental program, the Faculty of Dentistry has been operating for many years, The pediatric dentistry team is interested Study the factors that are related to oral health behavior, To prevent tooth decay in 5th grade students. Methodology: : This study model is a cross-sectional survey research, Send the interview form to the student's parents, Student interview form and oral examination carries. Tools used in research using the preceding framework. Sample population: The total number included in the study was 72 student who is studying Primary education grade 5, Sok Pa Luang Primary School Si Sattanak District, Vientiane Province. 2022-2023. Results: : The incidence of tooth decay in permanent teeth is 72 people: 29 people didn't find any carious teeth, Males without teeth are higher than females at 62.1% and a total of 43 people were found to have carious teeth and Females are 58.1% higher than males. Dental health care behaviors to prevent dental caries in the overall at a moderate (2.79±0.55), The relationship between sex, parent's age, the person the child lives with, the number of members in the student's family, the parent's occupation, the parent's education level, the average monthly income of the family and the amount of money the student comes to school with the behavior of taking care of dental health to prevent tooth decay. There is no relationship with the behavior of taking care of dental health to prevent tooth decay of students. Knowledge, Awareness about behavior dental health care to prevent tooth decay, Access to dental services, Dental caries information awareness and social support for dental caries prevention there is a positive relationship with dental health care behavior to prevent dental carries in students (p-value = 0.01). Conclusion: The incidence of tooth decay in students is 59.5%, It is considered that it is still very high that attention should be given to dental hygiene in many aspects and starting from the 1st grade so that students know and understand how to prevent tooth decay.