Objective To explore the possible mechanism of Xiaoyao Pill in improving the quality of oocyte in vitro. Methods Preantral follicles of 56 Kunming mice were separated and divided into the control group

the dispersing the stagnated liver-energy low

medium and high dose groups and the inhibitor group. Preantral follicles in each group were incubated respectively with 10% serum of normal rats

10% rats’ serum containing low

medium and high dose Xiaoyao Pill

as well as 10% rats’ serum containing high dose Xiaoyao Pill + 10 μmol / L K02288

all for6 days. The expressions of Smad1

Smad5 and Smad8 mRNA in oocyte were detected by real-time fluorescent quantitative polymerase chain reaction（ PCR） method. The expressions of Smad1

Smad5

Smad8

as well as phosphorylated Smad1 /5 /8（ p-Smad1 /5 /8） protein were detected by cellular immunofluorescence. Results Expressions of Smad1 mRNA and protein in the dispersing the stagnated liver-energy high dose group were higher than those in the control group（ P < 0. 05）. Expression of Smad5

Smad8 mRNA

protein and p-Smad1 /5 /8 protein in all dispersing the stagnated liver-energy groups were higher than those in the control group（ P < 0. 05）. There was no significant difference in expressions of Smad5 mRNA and protein between the dispersing the stagnated liver-energy high dose group and medium dose group（ P > 0. 05）

which were both higher than those in the low dose group（ P < 0. 05）.Expressions of Smad8 mRNA

protein and p-Smad1 /5 /8 protein were the highest in the dispersing the stagnated liverenergy high dose group（ P < 0. 05）. P-Smad1 /5 /8 protein in the inhibitor group was lower than that in the dispersing the stagnated liver-energy high dose group（ P < 0. 05）. Conclusion Xiaoyao Pill improving the quality of oocyte in vitro might be relate to up-regulating the expressions of Smad1

Smad5

Smad8 mRNA

protein and p-Smad1 /5 /8protein. The effect in the high dose group is the best.