Perléche is the disease that oftenly seen in growing children. It is worthwhile to study about the causes and its mechanisms of the occurrence. First of all, we employed basic retrospective epidemiologic survey on 2062 primary school children of age between 7 and 12 those who live in urban, farm, mountain and fishing village. The conclusions were the following : 1) Geographically, ruban showed lowest incidence, the next fishing village, third mountain village and farm hightest. The incidence of farm village was about 6 times than that of urban. 2) Male was more commonly affected. Through age distribution, group of 7 years old showed lowest incidence, then the incidence increased with rising of age and peak incidence in group of 11 years old. 3) Comparison between school children who take vitamins and milk, and who do not, the former marked obviously lower incidence. 4) Significant difference in incidence observed between farm and mountain of fishing village those who are similar level in dietary life.