The possible relationship between some morphological characteristics of soybeans and the contents of their bioactive components (tocopherols and isoflavones) was histochemically examined. It was found that tocopherols were distributed at high concentration in the cotyledon and that isoflavones were mainly localized in the plumule, hypocotyl, and radicle, which subsequently grow to form the adult plant. It was also found that the isoflavone content in soybeans with greencolored seed coats might be higher than that in soybeans with yellow seed coats.