The auther had studied on the debri index, calculus index and simplified oral hygiene index, which was made according to the oral examination criteria recommened by WHO in 1971. The examined persons were 14,825 persons who lived in large cities and rural area. The obtained results were as follows: 1. the simplified oral hygiene index were 1.81 in male and 1.54 in female who lived I large cities. In rural area, the simplified oral hygiene index were 2.23 in male and 1.92 in female. 2. the debri index, calculus index and oral hygiene index were lower in upper jaw than in lower jaw. 3. According to the aging, debri, index, calculus index and simplified oral hygiene index score wee increased. 4. Dental health education what had done was not so effective on oral hygiene.