Objective To investigate the effect of Qilin Pills（麒麟丸） on fertility in diminished ovarian reserve（DOR） model mice as well as the related mechanism. Methods Thirty-six female C57 BL/6 mice were randomly divided into 3 groups: blank group

model group and Qilin Pills group

with 12 mice in each group. Qilin Pills group was gavaged with 5.46 g/（kg·d） of Qilin Pills suspension

while the blank group and model group were gavaged with 20 ml/（kg·d） of 0.5% sodium carboxymethyl cellulose solution for 5 weeks. One week after the gavage

75 mg/kg of cyclophosphamide solution was intraperitoneally injected into the mice in model group and Qilin Pills group to induce the model of DOR

while 10 ml/kg of normal saline was intraperitoneally injected into the blank group

once per week for four weeks. The mice were tested daily for vaginal smears during treatment; after the medication

six mice in each group were randomly selected to be killed; Western blotting was used to detect hypoxia-inducible factor 1α（HIF-1α）

B-cell lymphoma-2/adenovirus E1 B interacting protein 3（Bnip3） and the homolog of autophagy key molecule yeast Atg6（Beclin1） protein expression. After seven-week normal feeding

the remaining mice were caged with male mice for 4 weeks

and the time of conception

number of conceptions

number of absorbed fetus and number of healthy offspring were observed. Results Compared to the blank group

the model group′s estrous cycle was disordered and stagnated at the estrous period; the conception time was prolonged

and the number of absorbed embryos increased; the protein expression of HIF-1α

Bnip3 and Beclin1 in the ovarian tissue was significantly increased（P<0.05 or P<0.01）. Compared to those of the model group

the estrous cycle of Qilin Pills group was restored

and the conception time was shortened; the HIF-1α

Bnip3 and Beclin1 protein expression was significantly decreased（P<0.05 or P<0.01）. Conclusion Qilin Pills can regulate the estrous cycle of DOR model mice and protect its fertility

which may be related to the regulation of HIF-1α/Bnip3/Beclin1 signaling pathway.