This report is a part of the health survey, which was carried out in the summer of 1973 on all adults older than 15 years of age, inhabiting in the sampled area. Thirteen villages out of 31 natural villages in Shindong Myon, Chunseong Gun, Kangwon Province, a typical rural area of Korea were randomly sampled. A little over 70 percent of the population sampled, or 1198 persons were examined. The health survey included laboratory screening tests, history taking, physical examination and consultation to specialists for selected cases. Diseases of circulatory system were classified by WHO ICD A-List (150). Hypertensive heart disease was defined by the criteria that was used in U.S. Health Survey, and hypertension by WHO criteria for the purpose of comparison. Results obtained were as followings: 1. The overall prevalence of the diseases of circulatory system per 100 adults examined was 8.6 for male and 9.9 for female. 2. Age specific prevalence of the diseases showed gradually increasing pattern as age advanced for both sexes. For example, the prevalence for 15~19 years old age group was 2.4/100 adults which increased to 24.8 when age reached over 60 years. 3. The most prevalent disease category, 3.6/100 adults, was A-88: other diseases of circulatory system that was consisted mainly of varicose vein and hemorrhoids; the second one was hypetensive heart disease, 2.4. 4. Female had higher prevalence than male in A-84: other form of heart diseases (4 times, arrhythmia, beriberi heart disease, and heart disease secondary to anemia), in chronic rheumatic heart disease (4.5 times), and in hypertensive heart disease (1.4 times); in other hand, cerebrovascular diseases (4.5 times) and diseases of arterioles and capillaries (1.5 times) occurred more frequently among males than females. 5. The proportion of hypertensive heart disease among persons with definite hypertension was 22.0% for male, 25.8% for female, and it increased gradually as age increased. Hypertensive heart disease among persons with borderline hypertension was 2.2%. Only 27% of hypertensive heart disease patients had previous treatment for hypertension. 6. The prevalence of definite hypertension per 100 adults examined (double blood pressure check with interval of 30~40 minutes) was 9.5 for male, 9.4 for female, with increasing pattern by advancing ages; marked increase occurred after age of 45 years for male and 35 years for female. The prevalence of hypertension in this study was much lower than that of the study on employees of Korea Electricity Comparny when compared with the same age groups. 7. Electrocardiographic findings on 105 heart disease suspects revealed left ventricular hyperspecific change in 4 persons. This study was supported by China Medical Board of New York Inc.