Objective To study possible mechanism of self-made Gengnian Decoction in the treatment of perimenopausal syndrome rats with deficiency of kidney Yang. Methods Eleven to twelve-month female rats with estrous cycle disorder and prolonged anestrus were selected

and 0. 5 ml /100 g hydrocortisone injection was intramuscular injected for 9 days to build perimenopausal syndrome rat model with deficiency of kidney Yang. The successful modeling rats were randomly divided into Gengnian Decoction group

Yougui Pill group

tibolone group and model group

20 in each group. Gengnian Decoction group was given self-made Gengnian Decoction solution 18 g /（ kg·d） by gavage

Yougui Pill group was given Yougui Pill（ 右归丸） solution 16 g /（ kg · d） by gavage and tibolone group was given tibolone solution 0. 294 mg /（ kg·d） by gavage. Another 20 four-month rats（ as young group） and 20 eighteen-month rats（ as aged group） were respectively given normal saline 4 ml by gavage. Each group was continuously treated for 15 days. The expressions of estrogen receptor（ ER） in hypothalamus and ER mRNA and expressions of Bax and Bcl-2protein in adrenal cortex of each group were detectetd. Results There was significant difference in positive expressions of ER in hypothalamus between Gengnian Decoction group and Yougui Pill group

model group and young group（ P < 0. 05 or P < 0. 01）

and there was no significant difference in positive expressions of ER mRNA in hypothalamus between these groups（ P > 0. 05）. The expression of Bax protein in adrenal zona glomerulosa of model group increased significantly

but that of Bcl-2 protein decreased significantly. Self-made Gengnian Decoction might decrease expression of Bax protein

increase expression of Bcl-2 protein（ P < 0. 05）. In adrenal zona fasciculate

Gengnian Decoction also might decrease expression of Bax protein

but had no significant influence on expression of Bcl-2 protein（ P > 0. 05）. In adrenal zona reticularis

Gengnian Decoction might decrease expression of Bax protein

significantly increase expression of Bcl-2 protein

and was superior to Yougui Pill group and tibolone group（ P < 0. 05）.Conclusion Self-made Gengnian Decoction could treat perimenopausal syndrome with syndrome of deficiency of kidney Yang the effect might be related to increasing expression level of ER in hypothalamus and decreasing expression of Bax protein in adrenal cortex and increasing expression of Bcl-2 protein in adrenal cortex.