【Abstract】Objective To study the effects of medroxyprogesterone acetate combined with metronidazole on inflammatory factors and TLR4/ NFκB signaling pathway in rats with endometritis. Methods Forty healthy SD rats were randomly divided into 5 groups. The control group was not treated. The other 4 groups were induced to model rat endometritis. On the second day after the successful modeling, the three groups were treated with medroxyprogesterone acetate (4 mg/kg/d), metronidazole (002 g/kg/d), medroxyprogesterone acetate and metronidazole (4 mg/kg/d+002)g/kg/d) was administered by gavage. After 14 consecutive days, the rats were sacrificed and samples were taken for examination. The pathological changes of uterus were examined by HE staining. The expressions of MMP2 and MMP9 in uterus were detected by immunohistochemistry. Results Different administration groups could alleviate the pathological damage of uterus in rats with endometritis. Compared with the control group, the expression of IL1, PGE2, MDA, NO, NFκB p65 and TLR4 in the model group was significantly increased, while the expression of SOD, MMP2 and MMP9 were significantly reduced (P＜005). Compared with the model group, the combined use can significantly reduce the expression of IL1, PGE2, MDA, NO, NFκB p65 and TLR4 in endometritis rats, and significantly increase the expression of SOD, MMP2 and MMP9. The expression of IL1 in the combined medication group was significantly lower than that in the metronidazole group. The TLR4 expression was significantly lower than that in the medroxyprogesterone acetate group and metronidazole group. The MMP2 expression was significantly higher than that in the metronidazole group, and MMP9 expression was significantly higher than that in medroxyprogesterone acetate group and metronidazole group (P＜005).Conclusion Medroxyprogesterone acetate combined with metronidazole has obvious therapeutic effect on endometritis in rats, affect TLR4/NFκB signaling pathway, improve inflammatory index and exert therapeutic effect on endometritis rats.