The present specification relates to a culturing method for cultured leguminous roots having an increased coumestrol content, the method being capable of mass-producing coumestrol, which is present ina very small amount in a leguminous plant, wherein the culturing method comprises the steps of: (a) germinating leguminous seeds in a culture medium to induce in vitro plants having cotyledons, hypocotyls, and radicles; (b) culturing, in a culture medium, at least one site of the cotyledons, hypocotyls, and radicles of the induced in vitro plant to induce site-specific cultured roots; and (c) multiplying the induced site-specific cultured roots in a culture medium, wherein the culture media contain nutrient components of NH4NO3, CaCl2.2H2O, MgSO4.7H2O, KH2PO4, and KNO3.