THE PREVALENCE OF FIRST PERMANENT MOLAR CARIES IN CHILDREN AGED 7-9 YEARS IN SD MUHAMMADIYAH WIROBRAJAN 3 YOGYAKARTA Hafeezeen Yeepaloh* Alfini Octavia** *)Student of School of Dentistry , Faculty of Medicine and Health Science Universitas Muhammadiyah Yogyakarta. **Lecturer of School of Dentistry , Faculty of Medicine and Health Science Universitas Muhammadiyah Yogyakarta Caries is a hard tissue disease caused by the activity of bacteria. Fermented carbohydrate as the result of bacteria activity is demineralized enamel and dentin , then followed by the damage of organic material. Aims. The aims of this study is determining the prevalence of first permanent molar dental caries in students of aged 7-9 years old of SD Muhammadiyah Wirobrajan 3 Yogyakarta and the comparison between caries disease toward age. Methods. It is a cross-sectional study and population of this research are children of primary school, aged 7-9 years old in grade 1st, 2nd, and 3th SD Muhammadiyah Yogyakarta Wirobrajan 3. The amount of subjects are 78 students and Stratified Random Sampling was used as sampling methods. ICDAS criteria was used to determine the prevalence of caries. The data obtained had been collected and analyzed by descriptive statistical methods. The comparison of the prevalence of first permanent molars dental caries towards the age groups was used by Chi-square test. Results. The prevalence of the first permanent molar dental caries in children aged 9 years old with are 20 teeth (6.4%) and the prevalence of caries of 7 years old is 1 (0.3%). Chi - square test showed that p < 0.05 so there is a significant result between the increased of age and the prevalence of caries. Conclusion. The highest prevalence of caries in first permanent molar in grade 1st, 2nd, and 3th SD Muhammadiyah Yogyakarta Wirobrajan is in aged 9 years old (6,4%) and the lowest at 7 years old (0,3%) . There is also significant result between the increasing of age and the prevalence of caries.