【Abstract】Objective Thirtytwo 8weekold male ApoE-/- mice were divided to two groups fed with highfat diet. The control group instilled with 0.9% saline, and an experimental group instilled with PM25 (30 mg/kg/day) for 8 weeks. We measured PM2.5 in whole blood by the ICPMS method. The plaque area of aorta, collagen, macrophage and smooth muscle cell were assessed by immunohistochemistry. The expression of IL6, IL12, iNOS, Arg1, CD206, ICAM1, MCP1 and LpPLA2 were detected by real  time fluorescence quantitative polymerase chain reaction. Results In PM2.5 group, we observed elevated heavy metal components (P＜005). The area of atherosclerotic plaque increased (P＜005), the number of macrophages increased (P＜005), the content of collagen decreased (P＜005), and the number of smooth muscle had no significant difference (P＞005). The expression of IL6, iNOS, IL12, ICAM1, MCP1 and LpPLA2 were increased (P＜005) and the expression of Arg1 and CD206 were decreased (P＜005).ConclusionPM25 exposure promoted the development of atherosclerotic plaques in ApoE-/- mice, which may be related to the change of expression of related inflammatory factors in atherosclerotic plaques.