Aim To explore the role of CD36 in foam cell formation and apoptosis and the time course of expression of CD36 gene and protein in macrophages foamy process induced by oxidized low dlensity lipoprotein (ox-LDL). Methods and Results Human myeloid leukemia U937 cells were incubated with ox-LDL (80 mg/L) for time course(6 h,12 h,24 h or 48 h) treatment. Total cholesterol in U937 cells increased from 143.5 to 419.2 mg/g protein. Flow cytometric analysis results revealed that CD36 protein expression increased from 6 h to 48 h induced by ox-LDL and was highest at 24 h. RT-PCR results showed that CD36 mRNA level increased with time order. The apoptotic cells were determined by flow cytometry and DNA fragmentation assay. Ox-LDL(200 mg/L) could induce U937 cell apoptosis after 24 h and increase after 48 h. Apoptosis were reduced by pre-incubation U937 cell with CD36 mono-antibody. Conclusions U937 cell could bind and internalize ox-LDL and formation in foam cell mediated by CD36. Later, apoptosis of U937 cell after incubated with ox-LDL also mediated by CD36. Accumulation of cholesteryl esters in U937 cells has no negative feedback control on CD36 gene and protein expression.