OBJECTIVE To s tudy the impr ovement effects of tilianin on the atherosclerosis （AS）model mice and its potential mechanism. METHODS Eight C 57BL/6J mice were taken as the normal group. Forty ApoE－/－ mice were randomly divided into model group ，tilianin low-dose ，medium-dose and high-dose groups [ 2.1，3.5，7.0 mg/（kg·d）] and simvastatin group [positive control drug ，3.5 mg/（kg·d）]，with 8 mice in each group. Normal group was given normal diet ，and other groups were given high-lipid diet to induce AS model. At the same time ，normal group and model group were given normal saline intragastrically ， administration groups were given relevant drug intragastrically ，once a day ，for 12 consecutive weeks. The levels of TC ，TG， LDL-C，HDL-C，Ox-LDL，IL-1β，IL-6，MCP-1 and TNF-α in plasma were determined. The pathomorphological changes of the aorta in mice were observed. The positive rate of ICAM- 1，VCAM-1 and PCNA in the aorta were determined. mRNA expressions of MMP- 2，MMP-9，TGF-β1，Smad2 and Smad 3 as well as protein expressions of TGF-β1，Smad2/3 and p-Smad 2/3 were also determined in aorta of mice. RESULTS Compared with normal group ，the plasma levels of TC ，TG，LDL-C，Ox-LDL，IL-1β， IL-6，MCP-1 and TNF-α in model group were increased significantly（P＜0.01），while HDL-C level was significantly reduced （P＜0.01）. Lipid plaques were formed in the aorta ，and the plaque area was large and caused severe stenosis of the lumen. mRNA expressions of MMP- 2，MMP-9，TGF-β1，Smad2 and Smad 3 as well as positive rate of ICAM- 1，VCAM-1，PCNA and protein expression TGF-β1，Smad2/3，and p-Smad 2/3 in the aorta were significantly increased （P＜0.01）. Compared with model group ， most of above indexes of medication groups were improved significantly （P＜0.05 or P＜0.01）. CONCLUSIONS Tilianin can inhibit the activation of TGF-β1/Smads signaling pathway and then inhibit the proliferation of vascular smooth muscle cells ，reduce ， inflammation and regulate lipid metabolism to inhibit the No.81960766） formation of AS.