Objective To explore the therapeutic mechanism of kidney-tonifying and blood-activating herbal medicine for anovulatory dysfunctional uterine bleeding(ADUB).Methods Thirty-seven ADUB patients were randomized into two groups.Group A(N=25)was treated with Gongxue Yin(mainly composed of Fructus Psoraleae,Radix Dipsaci,Fructus Corni,Pollen Typhae,Radix Notoginseng,Radix Codonopsis,Os Draconis,Concha Ostreae,Herba Hedyotis Diffusae),and group B(N=17)received medroxyprogesterone.One menstrual cycle constituted one treatment course and the treatment lasted 3 continuous courses.Histostain-plus(HP)immunohistochemical assay was adopted to test the Bcl-2 and Bax protein expression in endometrium of the two groups.Ten healthy volunteers served as the control.Results Bcl-2 protein expression was higher in endometrium of ADUB patients at proliferative stage or with proliferative changes than that at secretory phase of the normal control group(P0.05).Conclusion Both progesterone and kidney-tonifying and blood-activating herbal medicine decrease endometrial Bcl-2 protein expression and increase Bax expression,by which inducing the endometrial cell apoptosis in patients with anovulatory dysfunctional uterine bleeding.But their detailed mechanism may be different.