Purpose: This study was designed to investigate the effects of Gaeullijin-Tang(GIT) on the progression of the estradiol valerate(EV)-induced polycystic ovaries(PCO) in rats. Methods: PCO was induced by single intramuscular injection with estradiol valerate(EV)(4mg) in female rats. Normal group(n=8) were injected with sesame oil and orally administrated distilled water for sixty days. PCO control group (n=8) were injected with EV and orally administrated distilled water for sixty days. GIT treated group(n=8) were injected with EV and orally administrated GIT for same duration. At the end day of experiment, we measured weights of body, ovaries, adrenal glands, uterus and contents of serum androsternedione (ADD) and total estrogen. The histomorphometrical changes of ovaries were also evaluated. And we observed the NGF and CRF expression by immunohistochemistry. Results: The results were as follows - The weights(mg) of ovaries in GIT treated group($75.5{pm}4.3$) were significantly increased(p<0.001) compared with PCO control group($54.3{pm}4.5$). - The numbers of mature follicles in GIT treated group($5.3{pm}1.2$) were significantly increased(p<0.05) compared with PCO control group($3.5{pm}1.2$). - The numbers of corpora lutea in GIT treated group($1.8{pm}1.3$) were significantly increased(p<0.05) compared with PCO control group($0.3{pm}0.7$). Conclusion: From the above results, we concluded that Gaeullijin-Tang(GIT) contributes to stimulating normally ovulation by decreasesing ovarian NGF concentrations.