Objective To explore possible functional mechanism of Buyi Yingwei Fang（ 补益营卫方） in preventing skin aging. Methods Ten 3-month old C57 BL /6 female mice were set as the young group. Forty mice of 14 months old were randomly divided into the aging group and the Buyi Yingwei Fang high

middle and low dose groups

with 10 in each group. The Buyi Yingwei Fang high

middle and low dose groups were respectively gavaged with 6

3

and 1. 5 g /（ kg·d）

last for 6 weeks. Using immumofluorescence method to examine the expression of epidermal keratin K5 and K6 in skin of aging mice in each group. Results Compared with the young group

the expression of epidermal keratin K16 in mice in the aging group remarkably increased（ P < 0. 01）; Compared with the aging group

the expression of epidermal keratin K16 in skin of mice in the Buyi Yingwei Fang high

middle and low dose groups remarkably decreased（ P < 0. 01）. The Buyi Yingwei Fang middle dose group had the largest effect in inhibiting the expression of K16. The difference had statistical significance compared with that of the Buyi Yingwei Fang low dose group（ P < 0. 01）. The difference had no statistical significance compared with that of the Buyi Yingwei Fang high dose group（ P > 0. 05）. The difference had no statistic significance while comparing the expression of epidermal keratin K5 in skin of mice in each group（ P > 0. 05）. Conclusion Buyi Yingwei Fang may function to staving the skin aging by inhibiting the expression of epidermal keratin K16 of aging skin.