【Abstract】Objective：To investigate whether high fat/high cholesterol diet（Paigen diet） could lead lipid accumulation in pulmonary tissues of C57BL/6J mice. Methods：Sixty six C57BL/6J male mice were randomly divided into two groups and were treated with regu－lar diet and high fat/high cholesterol diet respectively. The pulmonary tissues were collected at the 12th，16th week and the 20th week after feeding respectively. The aortas atherosclerotic plaque and lipidosis in pulmonary tissues were determined by oil red O staining. A549 cells were cultured in vitro and were treated with different concentrations of low density lipoprotein（LDL） to observe the effect of cholesterol loading on alveolar lipid accumulation in vitro. Results：Aorta atherosclerosis plaques were observed in high fat/high cholesterol diet treated C57BL/6J mice. Oil red O staining of pulmonary tissues at different time points suggested that high fat/high cholesterol diet could lead to time-dependent lipid accumulation in pulmonary tissues of C57BL/6J mice. Oil red O staining of A549 cells implied that there was a dose-effect relationship between the lipidosis and the concentrations of LDL. Conclusion：High fat/high cholesterol diet could lead to time-dependent lipid accumulation in pulmonary tissues of C57BL/6J mice，which partly due to the disruption of lipid homeostasis in alveolar type Ⅱ epithelial cells.