Objectives: This study was designed to investigate the effects of Jokyeongjongok -Tang(JJT) 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)(4 mg) 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. JJT treated group(n=8) were injected with EV and orally administrated JJT for same duration. At the end day of experiment, we measured weights of body, ovaries, adrenal glands and uterus. The histopathological 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 of JJT treated group($58.4{pm}9.4$) were significantly increased(p<0.01) compared with PCO control group($42.3{pm}8.5$). - The numbers of mature follicles of JJT treated group($10.1{pm}2.5$) were significantly increased(p<0.01) compared with PCO control group($6.1{pm}2.1$). - The numbers of cystic follicles of JJT treated group($1.8{pm}1.4$) were significantly decreased(p<0.05) compared with PCO control group($3.8{pm}1.5$). - The expressions of NGF-immunoreactive cells in the ovaries of JJT treated group were weaker than PCO control group. Conclusions: From the above results, we concluded that Jokyeongjongok-Tang (JJT) contributes to a normal maturation of follicles and has the effects of promoting a normal ovulation. And these effects may be related with the decreased NGF activities in the ovaries.