This research reached conclusions to prepare indications for activity of Oral health Instruction of the first grade in an elementary school by several items of Oral examination and investigation. 1. The frequency of brushing their teeth of the children that were examined was generally two times a day(64.42%) : it showed that it was the highest after breakfast (30.08%), and hardly any brushed their teeth after lunch(6.36%). 2. Most of the toothbrushes used were for children(97.46%), and the proper time to change their toothbrushes was less than two months(65.25%), but 31.37% of them used their toothbrushes for more than three mouths. 3. They usually used toothpaste. Those using toothpaste were 64.41%. By the way, for adults was the percentage 31.36%, and for those including fluorine it was 74.58%. 4. They mainly ate cookies, beverages, (coke, cider, etc.), fruit, bread, milk and so on for their dessert. 5. Most students had dental plaque (95.76%) : 14.4% of then had calculus and 23.73% had gingivitis. 6. The results of disclosing showed that twelve anterior teeth were colored. The Mandible was comparatively more severe than the Maxillary in the colored -degree. the low -right - laterial incisor was the most severe and the right central incisor was the most severe of the Maxillary. 7. The pressure of tooth - brushing showed that half of the students brushed their teeth severely. The width of the brushing movemtnts was more than 8mm for 51.70%, 5-8mm for 33.05% and less than 5mm for 15.25% Therefore 66.5% of them were shown to move their brushes insufficiently or oppositely. 8. When they brushed, the children who opened their mouth while brushing were more than those who kept their mouth closed.