Objective To observe the effect of Bushen Jianpi Formula（ 补肾健脾方） on ovarian function in natural aging mice and its possible mechanism. Methods Randomly divided 48 C57 BL/6 J female mice of 9 months old（ natural aging models） into model group

positive control group

Bushen Jianpi Formula high and low dose group

with 12 mice in each group. Other 12 mice aged 2

3 months were selected as the youth group. The Bushen Jianpi Formula low and high dose group were given Bushen Jianpi Formula 0. 51 and 2. 55 g/（ kg · d） by gavage respectively

while the positive control group were given Dehydroepiandrosterone tablet 1. 25 mg（ kg·d） by gavage

and the youth group and model group were given 0. 2 ml distilled water by gavage

all for 3 months. Compared estrous cycle

farrowing amount

numbers of retrieved oocytes in vitro fertilization

mature oocytes

fertilized eggs

cleavage number and number of blastocyst and measured expression of newborn ovary homeobox gene（ Nobox） protein and mRNA in ovary of mice in different groups. Results Compared with the youth group

the whole estrous cycles times

proportion of proestrus and oestrum in whole cycle

farrowing amount decreased in the model group. The number of retrieved oocytes in vitro fertilization

mature oocytes

fertilized eggs

cleavage number and number of blastocyst were also reduced with reduction of the expression of Nobox protein and mRNA in ovary（ P

<

0. 05 or P

<

0. 01）.Meanwhile

the number of retrieved oocytes in vitro fertilization

mature oocytes

fertilized eggs

cleavage number and number of blastocyst in the Bushen Jianpi Formula high dose group were higher than that in the model group

and the expression of Nobox protein and mRNA in the ovary increased（ P

<

0. 05 or P

<

0. 01）. Conclusion Bushen Jianpi Formula could improve the reproductive ability and egg quality of natural aging mice

and its mechanism may be related to increasing Nobox transcription factor expression in the ovary of mice.