Aim To observe the effect of Alisma Decoction on lipid deposition and the expression of LXRα and ABCA1 on macrophagic foam cell formation.Methods Macrophagic foam cell formation was established after induction with oxidized low density liprotein (ox-LDL) (50 mg/L) and Dil-ox-LDL(10 mg/L)for 24 h respectively and then the cells were intervened with 20% Alisma Decoction-containing serum. Oil red O staining and fluorescence microscopy were used to detect the lipid deposition in cells. RT-PCR and Western blot was utilized to detect the expression of LXRα and ABCA1.Results Macrophagic foam cell formation was established sucessfully after the stimulation with ox-LDL(50 mg/L) and Dil-ox-LDL(10 mg/L). Compared with the control group, lipid deposition was increased significantly in the model group, while lipid accumulation was obviously reduced in macrophage cells after treated with Alisma Decoction-containing serum. The expression of LXRα showed a low level in both the control group and model group. However, after intervened with the Alisma Decoction-containing serum,the expression of LXRα increased distinctively in macrophage cells which was pretreated with ox-LDL. As to ABCA1,the model group expressed much more greatly than the control group. And the macrophage cells treated with the ox-LDL and Alisma Decoction--containing serum group had a high level expression ,but it is lower than the model group.Conclusion Macrophagic foam cell formation was sucessfully established after induction with oxidized low density liprotein (ox-LDL) (50 mg/L) and Dil-ox-LDL(10 mg/L). Alisma Decoction can decrease the lipid deposition in the process of macrophagic foam cell formation, and it may depend on the way of upregulating the expression of LXRα.