This study was carried out to evaluate the ostrogenic/antiandrogenic activity of Puerariae Radix in Sprague-Dawley rats. It has known that diverse phytoestrogen were included in some Puerariae Radix, especially in Pueraria mirifica. The Uterotrophic assay and Hershberger assay were performed to evaluate the ostogenic/antiandrogenic activity of various Puerariae Radix (Pueraria thunbergiana, Pueraria mirifica and Butea superba). In Uterotrophic assay, the extracts of Puerariae Radix were administered subcutaneously to immature female SD rats from 19 to 21 days of age. The wet uterus and vaginal weighs significantly increased in the group only treated with extracts of Pueraria mirifica. But, in Hersh-berger assay, all extracts of Puerariae Radix did not show any effects in the castrated rats. These results suggest that Pueraria mirifica has not undrogenic/antiandrogenic effect but potent estrogenic effect. It is possible that components of Pueraria mirifica may act as endocrine disruptor in human body.