This research aims to describe Mentawai cultural values in the younger generation, especially elementary school students at State Elementary School 02 Matotonan, South Siberut sub-district, Mentawai Islands district, West Sumatra Province. Most students do not understand and do not practice Mentawai cultural values in their daily lives, whether in the community, school or family. The lack of understanding of Mentawai cultural values encourages students who truly identify with Mentawai culture to slowly become individuals who do not love Mentawai culture. Several factors such as rapid modernization, progress and sophistication of science, parenting styles that prefer modern and efficient are the causes of the decline in Mentawai cultural values. The method used is a qualitative method with an ethnographic and anthropological approach, data is collected in the form of qualitative data. Data collection techniques are observation and interviews as well as documentation studies. The research findings are that there is a cultural event held every Matotonan village birthday by requiring every child to wear luat and beads every Thursday at school and making it mandatory every day in August every year. The pattern implemented by villages and schools is carried out periodically and this gives significance to the existence of Mentawai cultural values in elementary school 02 Negeri Matotonan. These Mentawai cultural values have become the awareness of all parties, especially families, schools and the community, becoming the driving force and front guard in maintaining the preservation of Mentawai cultural values.