The distribution of thiamine in the seed of several kinds of bean was studied by the histochemical method and chemical assay. In the case of broad bean, Azuki bean, sasage bean and kidney bean, thiamine concentration in embryo was heavier than in cotyledon. But in the case of peanuts and soybean, thiamine concentration in cotyledon was rather heavier than in embryo. On the other hand, in the case of pea, thiamine concentration in embryo was almost the same as in cotyledon. Summing up the above, seven kinds of bean could be classified into three groups.