The author has studied on health including dental diseases of the people in Mikurajima, one of the Izu Islands. This island is much different from the others of Japan on social and economical points of view. It has a physician in a clinic run by health insurance as the only medical institution. Health center services are scarcely given by the com-petent health center located at Miyake-jima, on account of geographical handicap there. Population is 315 and its density is 17.6 persons per 1m2. Population structure rather shows tural type.The results were as follows.1) As regards vital statistics, birth rate was 34.4 per 1000 population (1959) and death rate was 20.1 per 1000 population (the average of those 5 years from 1953). Both of them were much higher than the average of all Japan.2) Concerning physical constitutions of the people, their weights were more than the average of all Japan, and over average in the youth of male and in the age of 30 of female. Also it was showed that the girths of their chests were wider than the average of all Japan in the youth of male and the old age of both of male and female. There was no clear difference of the girths of upper arms between of these people and of all Japan, which was considered as one of nutritive indexes, 3) From nutrition survey, the followings were observed.i) Kinds of taken foods in a year were much influenced by each season especially by its weather.ii) People have taken less total quantities and higher total Calory than the average of all Japan.iii) People had taken more quantities of fat and carbohydorate, less protein especially animal protein, less Ca, more P and less all Vitamins than each. quantities of the average of all Japan.4) Rate of medical consultation was one third of all Japan. The rate was highest in the ages, between from 30 to 39, In May and Novembe, the rates were high. The most rate was by common cold, and the next was digestive organs including dental disease which occupied one-third of this consultation in a year.5) Incidence was rather low.6) As specific diseases of this district, there were many dermatological diseases and a few food poisonings by fishes which had showed intoxicated symptom. Besides, it was guessed that there were Filariasis from Hydrocele patients, and Shichito fever which was considered as one of tsutsugamushi diseases.7) There were many patients of dental caries and it was considered that this fact concerned greatly with many factors including geographical condition, an unbalanced diet by season, too much carbohydorate, taking unbalance of Ca and P, and other food life.8) Incidence of patients of dental caries was 85.1% and it was too high especially in female. Incidence of number of dental caries were 43.2% of total temporary teeth and 20.6% of total permanent teeth. The grades of dental caries were 34.6% of C1, 33.7% of C2, 31.7% of C3 amongtemporary teeth and 30.5% of C1, 33.8% of C2 and 35.7% of C3 among permanent teeth.9) There were comparatively a few patients whose tartars adhered to teeth and smally number of gingivitis and of alveolar pyorrhea.10) There were many egg-round sharped row of teeth in male and female, and its rate was 93.1% of all examinees. Normal occlusion was 68.3% of all of them.11) Mottled teeth, Hutchinson's teeth, dental hereditary, scorbute and other dental specific diseases were not found there.12) In respect of general health examination, it was found that there were comparatively many people who showed symptom of beriberi. The tendencies were not seized through the measurement of blood pressure and urine examinations.13) Concerning classification of death cause, the group of contaminatious diseases had generally decreased recently.