Objective:To study the effect of Ziyin Pinggan renal decoction on serum sex hormone level and expression of Bax and bcl-2 protein in uterine tissue of perimenopausal model rats, and to elucidate its therapeutic mechanism. Methods:Sixty female SD rats were randomly divided into 6 groups, 10 in each group:control group, model group, tibolong group (0.3 mg·kg^-1), Ziyin Pinggan renal decoction at a low concentration (0.4 g·kg^-1), medium concentration (0.8 g·kg^-1), and high concentration (1.6 g·kg^-1). The control group was fed routinely, and both ovaries were surgically removed in the groups to establish a perimenopausal rat model for 6 weeks. HE dyeing was performed to observe the structure changes, blood sample was taken from the abdominal aorta to detect estradiol (E2) and progesterone (PROG), follicle-stimulating hormone (FSH), inhibin A inhibin (Inh-A), B (Inh-B), testosterone (T) and luteinizing hormone (LH), prolactin (PRL), gonadotrophin releasing hormone (GnRH) level using enzyme linked immunosorbent assay, Western blotting was used to detect the expression levels of apoptosis-promoting gene (Bax) and B-lymphoma-2 gene (Bcl-2) protein in the Bcl-2 gene family of rat uterine tissues in each group. Results:Rats in the low, medium and high concentration groups of Ziyin Pinggan renal decoction had clear tubular structure, obvious thickening of endometrium, columnar epithelium, extremely rich glands, rich blood vessels, and secretory vacuoles at the bottom of cells. Compared with the model group, serum LH, E2, GnRH, PRL and T levels were significantly decreased in the low, medium, high concentration groups of Ziyin Pinggan renal decoction (all P<0.05), high concentration groups serum FSH[(8.23±1.00) mIU·ml^-1,(10.36±1.03) mIU·ml^-1], PROG[(11.18±1.18) ng·ml^-1,(11.53±1.22) ng·ml^-1], Inh-A[(10.11±1.21) ng·L^-1,(11.92±1.18) ng·L^-1] and Inh-B[(7.28±0.99) ng·L^-1,(8.98±1.11) ng·L^-1]levels were significantly increased (P<0.05). Compared with the model group, the expression of Bcl-2 protein in the uterine tissues of rats in the low, medium and high concentration groups of Ziyin Pinggan renal decoction was higher than that in the model group[(3.78±0.44) pg·ml^-1, P<0.05], and the Bax protein level in the uterine tissues of rats in the low, medium and high concentration groups of Ziyin Pinggan renal decoction was decreased[(9.44±1.10) pg·L^-1, P<0.05]. Conclusion:Ziyin Pinggan renal decoction can significantly reduce the content of endocrine hormone and Bax expression level in perimenopausal model rats, improve the expression of Bcl-2 protein, and improve the structure of uterine tissue.