In order to clarify the positioning of blood pressure of the Japanese in international relationship, comparative studies were made on the blood pressure of the population in various parts of the world. According to the data of average systolic blood pressure reported in 211 papers treating epidemiology on the blood pressure of Japanese until 1970 and 86 papers outside Japan until 1969, the systolic blood pressure of the Japanese population, especially in the northeastern　parts, was higher than in the other countries and its distribution, according to the data on standard deviation of systolic blood pressure, was wider, although there were different levels and distributions of systolic blood pressure in the northeastern parts of Japan. In almost all groups blood pressure level rose with advance in age based on data of average blood pressure by age, In the group of high blood pressure in the same age group the blood pressure in the young age group the blood pressure level at higher age was also shown to be high.

In order to scrutinize　the shifting of individual blood pressure level over long time, follow-up studies were made in three villages in the northeastern parts of Japan. Oinomori(population; ca 700) and Kanaya(p; ca 1400) in Aomori prefecture and Nishime(p;ca 5000) in Akita prefecture were selected. Blood pressure was determined once or twice a year by mass survey from 1954, 1958 and 1957 respectively up to 1975. The level and distribution by age and sex in three village were differences in blood presure corresponded to the death rates　from cerebrovascular diseases in the death rates from cerebrovascular diseases in the middle age in the areas. The difference in blood pressure was considered to be related to the difference in the way of living such as traditional high salt intake, housing conditions and to the difference between two areas of single rice crop district (Akita) and apple producing district (Aomori) by retrospective epidemiological studies.

The difference in blood pressure in winter and summer was almost always found to the significant irrespective of sex, age-group or location by observation on the blood pressure of the same 831 inhabitants during first five years and there was an obvious elevation in the blood pressure in winter amongt the inhabitants of northeastern parts of Japan.

The reduction in the mean of systolic blood pressure pressure by age and sex and change in the blood pressure distributions　were observed during entired period. The level of blood pressure of the inhabitants tends to become lower compared to the level at the begining in the late 1950s and only in the middle age group but also in such a young group as middle school children. And these　changes were considered to be related to improvement of living conditions such as the reducing of times miso soup eaten a day and the number of cups taken.

The blood pressure level was different individually from the childhood. Statistical significant correlation was found between the blood pressure level in a young age and the level in their adult age. The resemblance coefficients between the blood pressure of parents and child by age and sex were almost positive, but the coeficient between the blood pressure of husband and wife in the same population were not significant based on the data of average blood pressure level for each person.

The birth cohorts, as established in the late 1950s in three villages respectively except the person moving in or out during the entired period, were followed by death certificate and other surveillance to indentify deaths occuring in subsequent year up to 1975. Person years of observatin is used for calculating death rates in cohort study, especially in the death rates from cerebrovascular diseases at every 10 mmHg level in the distribution of blood pressure. According to the results obtained in this study it become obvious that a person whose blood pressure level was high from the younger age are apt to get attack to death from cerebrovascular diseases. The type of cerebrovascular diseases was almost haemorrhagic in the cases of the group under 60 years although the proprtion of cerebral haemorrhage and cerebral infarction was half and half in the old age group. The death rates from cerebrovascular diseases in three villages were different in parallel with the levels of blood pressure of the population.

The propotion of ischemic heart diseases among causes of death as a whole was very low in these populations in the northeastern parts of Japan.