Dental caries is one of the main factors to cause the teeth to be lost. Diet is the important factor in the development of dental caries. Today, Dental plaque control, Fluoride to pical application, Fissure sealing and Diet control are used to prevent dental caries. By the five day diet diary, the author surveyed the food in take of 600 infants aged from 10 to 12 in the subures of Seoul. Using the cariogenic food intake analysis form, the detergent food intake analysis form and the basic food intake analysis form, the data were collected, analysed and discussed. After discussing the results, the author concluded as follows : 1. The intake frequency of meals per day was 4.91 times, of which 2.74 times taken at meals and 2.17 times at between meals. Girls(5.00) had taken more times than boys(4.69) at meals an between meals. 2. The intake frequency of cariogenic food per day was 1.93 times, Liquid cariogenic food was taken 0.05 times at meals, and 0.58 times at between meals. Solid cariogenic food was taken 0.05 times at meals, and 0.08 times at between meals. Girls(1.67) had taken cariogenic food more times than boys(1.46). 3. The percentage of intake without detergent food of each intake time per head per day was 71.62% at meals, and 85.7% at between meals. The highest percentage was at evening meals. Boys(44.00%) had taken more detergent food than girls(56.71%). 4. Both boys and girls had the basic food intake taken enough only in 2nd group of basic food, lacking in the other 4 groups. Girls had taken the basic food comparatively more times than boys.