Estradiol is used to treat ovarian inactivity and persistent corpus luteum, common problems causing economic losses in animal industries. Estradiol can cause untoward side effects and hormone residues in milk and meat. Chinese herbal medicine may have similar effects to estradiol, without the adverse side effects. The authors created a Chinese herbal medicine, Cu Yun Guan Zhu Ye (CYGZY), by combining 0.2 g/ml Hong Hua (Carthamus), 0.4 g/ml Yin Yang Huo (Epimedium) and 0.4 g/ml Yi Mu Cao (Leonurus) suspected to have mild estrogen-like effects. The objectives of 4 randomized, controlled and blinded experiments were to compare the light and electron microscopic effects of CYGZY and estradiol on: 1) vaginal and uterine epithelium, 2) ovarian follicular development, 3) endometrial alkaline phosphatase (AP) and 4) uterine and ovarian blood vessels in-vivo in murine models. The hypothesis of the studies was that CYGZY would have effects on the vagina, uterus and ovaries that were similar to, but milder than, estradiol. The CYGZY increased vaginal keratinization and thickness, uterine thickness and glandular development, promoted ovarian follicular development and maturation and endometrial AP activity in the same way, but significantly less than estradiol and significantly more than normal saline. The CYGZY also significantly increased arteriole and venule diameters and the number of connections to capillary beds compared to normal saline. Overall CYGZY had a stronger effect than each component herb alone. The CYGZY may provide a novel, effective treatment for ovarian inactivity and persistent corpus luteum, with less untoward side effects than estradiol.