Soico-medical survey was carried out on six hundred and thirty Korean households in the cities of Tokyo, Osaka, Kyoto, Nagoya in Japan from Nov. 1972 to Dec. 1972, and following results were obtained. 1. Age distribution of households showed the highest occurrence in the group of 40 to 49 years of age in the both sexes. Families with five members showed highest occurrence, and the average number of familial members was 5.7 persons per one household. 2. More than half of the householders were some independent enterprisers rather than to be the employees and most of the households had one familial member engaged in more or less liberal profession. 3. 19.4% of households moved into these cities form 1941 to 1945. 4. 40.5% of all the households had their own houses. The possession rate of noe's own house was higher in the households which had long period of residence in Japan. 5. 83.5% of all household had various medical insurance. And the 6.2% of the household which had no insurance stated that the reason for not being affiliated was "because to be the foreigner". Household of shorter dwelling period had less tendency to be affiliated to the various insurances. 6. In 41.3% of all the households, average medical expenditure amounted to 1000-5000Yen per month. And only 25.6% of household stated that they do not worry about the medical expenditure for the futures. 7. 66.3% of households were consulting to medical doctors for their sickness, such as toothache, severe coughing, porfuse sputum., children's fever and stomach pain etc. 8. 59.4% of households were using the facilities of health center services. The health center service was used mainly for individual health service rather than the environmental aspect. And 19.8% of households were not aware of health center activities. 9. It was found that 23.5% of households received the screening test of the adult diseases showed as following; stomach cancer, 8.9%; hypertension, 7.9% ; diabetes mellitus, 2.1% ; and uterus cancer, 1.6%. 10. Birth control was carried out in 17,3% of households but not in 52.5%. The chief reason of birth control was "because of poor maternal health" (40.4%) or " should no be done"(5.4%). 11. Most of them are obtaining the knowledges and information on family plannings, public nuisance problems and nutritions etc. by means of the mass communications, while those on preventing diseases and the environmental hygiene through the administrative organizations.