Abstract: To study the interactive effects of zearalenone (ZEA) and soybean isoflavone (ISO) on growth performance, development of reproductive organs and transcription of estrogen receptor genes in replacement gilts, ninety 75-day-old female crossed-bred pigs (Duroc × Landrace × Yorkshire) were randomly allocated to nine diet treatments with 5 replicates in each treatment of 2 pigs per replicate during the 21-day research. The experiment was a 3×3 factorial design using a none-soybean meal diets with the level of ZEA at 0, 0.5 or 2.0 mg·kg^-1 and the addition of ISO at 0, 300 or 600 mg·kg^-1. The results showed that interaction of ZEA and ISO in diets has no significant influences on the average daily gain (ADG) and average daily feed intake (ADFI) in the replacement gilts (P>0.05). ISO could enhance the increased weight of the reproductive organs and the width of vulva induced by ZEA with 0.5 mg·kg^-1 in diets. However, ISO with 300-600 mg·kg^-1 in diets could reduce the increased weight of reproductive organs and edema of vulva induced by ZEA with 2 mg·kg^-1 in diets of replacement gilts（P<0.05）.Simultaneous provision of ISO and 2 mg·kg^-1. ZEA to replacement gilts increased the mRNA transcription of ERα, and reduced the mRNA transcription of ERβ in uterus and vagina compared with the pigs offered the diets containing 2 mg·kg^-1 ZEA alone. The results suggested interaction of ZEA and ISO in diets has no significant influences on ADG and ADFI in the replacement gilts. The estrogenic effect of ZEA would be reinforced when coexistence of ISO and low dosage of ZEA (0.5 mg·kg^-1) in the diets. While ISO could offset the estrogenic effect of ZEA when the diets containing the high dosage of ZEA (2 mg·kg^-1). The effects of ZEA and ISO on the development of reproductive organs in replacement gilts were mediated through the dual estrogen function of ISO and changing the mRNA transcription of ERs in the reproductive organs.