The aim of this study was carried to the induction of follistatin-like 1 (FSTL1) in rat myometrium tissue by exogenous estrogen. PCR was performed by using estrogen treatment after ovariectomy of myometrium mRNA and only ovariectomy of myometrium mRNA and on ovariectomy of myometrium mRNA in rat normal uterus tissue. The PCR products were visualized on agarose gel (1.2％) electrophoresis. FSTL1 mRNA expression level was significantly higher (**P<0.001 or *P<0.05) in estrogen treatment after ovariectomy than in only ovariectomy, and was significantly higher (**P<0.001) in no ovariectomy than in estrogen with treatment after ovariectomy. In conclusion, Although the mechanisms of FSTL1 gene were uncertain, It also might be inducted by exogenous estrogen. And also it is thought to be related to the estorgen mechanism.