Aim To investigate the effect of serum amyloid P component (SAP) on the formation and development of foam cells by observing the formation of foam cells, the morphology of lipid droplets and the expression of lipid droplet surface protein molecules. Methods THP-1 cells were induced to differentiate into macrophages after 48 hours of PMA treatment, and then foam cells were induced by oxidized low density lipoprotein (ox-LDL) combined with lipopolysaccharide (LPS) as control group. Different concentrations of SAP (0,0 mg/L) were added to the experimental group for intervention. Oil red O staining was used to analyze the effect of SAP on foam cell formation and lipid accumulation, and Bodipy493/503 staining was used to observe the morphology and quantity of lipid droplets in foam cells under fluorescence microscope. The lipids in the foam cells were extracted and the contents of triglyceride (TG) and cholesterol ester (CE) in the foam cells were quantitatively determined by kit. Western blot was used to analyze lipid droplet surface related proteins, such as acetyl coenzyme A carboxylase (ACC1), adipogenesis related protein (ADRP), 47 kDa telopenin (TIP47), histone demethylase (JMJD3), fatty acid synthase (FAS). Results Oil red O staining and Bodipy493/503 staining showed that intracellular lipid droplets in the experimental group were larger and more numerous, and the trend was more obvious in the 20 mg/L SAP intervention group than in the 10 mg/L SAP intervention group. The results showed that SAP could enhance the expression levels of ADRP, TIP47, JMJD3 and FAS. Except for the same expression level of FAS in different concentration of SAP intervention group, the expression level of FAS increased with the increase of SAP concentration. Conclusion SAP can promote the formation of foam cells and enhance the accumulation of lipid, SAP can enhance the expression of related lipoproteins.