Arterial atherosclerosis sequentially manifests as three major types: lipid spots and stripes, atheromatous and fibrous atheromatous plaques, and complex lesions. According to the process of its occurrence and development, it can be subdivided into six types. The first type is lipid spots, which are small yellow spots on the arterial intima that gradually develop into the second type, lipid stripes, where some yellow stripes appear on the arterial intima. Then there is the third type, pre-lesional plaque, where more lipid droplets appear extracellularly. The fourth type is the atheromatous plaque, where lipids accumulate excessively and form lipid pools, and the intimal structure will be damaged. The fifth type is the fibrous atheromatous plaque, which is the most characteristic lesion of arterial atherosclerosis. The sixth type is a complex lesion, representing a severe condition.