Objective To explore the mechanism of prevention and treatment of atherosclerosis by Wenban Decoction（稳斑汤）. Methods Twenty SD rats were randomly divided into blank group and Wenban Decoction group of low

medium and high concentrations

with 5 rats in each group. Wenban Decoction low

medium

high dose groups were given Wenban Decoction 4. 275

8. 55

17. 1 g/（ kg·d） gavage

and blank group was given 4 ml distilled water

once a day

continuous gavage for 7 days. Eight days after intragastric gavage

blood was taken from the abdominal aorta and the serum was separated after centrifugation. Mouse macrophages were cultured in vitro and divided into blank control group

model group

rapamycin group

and low-

medium-

and high-concentration group of Wenban Decoction

with 6 holes in each group. Except for the blank control group

macrophage foaming was performed in all other groups. The blank control group and model group were cultured with 10% rat blank serum; the rapamycin group was cultured with 10 μl/hole of rapamycin（ final concentration of 10 nmol/L）; the low

medium

and high concentrations of Wenban Decoction were treated with 10 % Wenban Decoction low

medium and high concentration of serum containing 200 μl/hole culture. After 48 hours

the cells were collected and the autophagosomes were observed under transmission electron microscope. The expression of LC3 B and Beclin 1 protein in each group was detected by Western Blot. Results Under transmission electron microscope

there were no obvious autophagosomes in the blank control group

and a small amount of autophagosomes were seen in the model group. Compared with the model group

the number of autophagosomes in each concentration of Wenban Decoction group and the rapamycin group was significantly increased

and the number was larger in rapamycin group. Compared with the blank control group

the expression of LC3B and Beclin 1 protein in the other groups increased（ P < 0. 05）; compared with the model group

the expression levels of LC3B and Beclin 1 protein in each group of Wenban Decoction and rapamycin group elevated（ P < 0. 05）; Compared with rapamycin group

there was no significant difference in the expression level of LC3B and Beclin 1 protein in the high concentration group of Wenban Decoction（ P > 0. 05）. Conclusion Serum containing Wenban Decoction can up-regulate the expression of macrophage foaming autophagy-associated proteins LC3B and Beclin 1 and promote autophagy of foamed macrophages

thereby inhibiting the progress of macrophage foaming

which may be one of the molecular mechanisms of prevention and treatment of atherosclerosis by Wenban Decoction.