It is very clear that hyperlipemia is a risk factor of atherosclerosis. To further understand the role of lipoproteins, especially oxidized lipoproteins in atherogenesis, we examined the effects of oxidized low density lipoprotein (OLDL) and very low density lipoprotein (OVLDL) on platelet-derived growth factor Bchain (PDGF-B) expression in monocytes. Methods Low density lipoprotein (LDL) and very low density lipoprotein (VLDL) were isolated from normal blood donors by density gradient ultracentrifugation. After exposed to LDL, OLDL, VLDL, and OVLDL for 24 hours and subsequently exposed to lipoprotein-free media for 24 hours, respectively, monocytes were used to immunocytochemical staining by anti-PDGF-B antibody, meanwhile the conditioned by cultured monocytes media were collected. and their influences on 3H-TdR incorporation into DNA of smooth muscle cells were observed.Results Monocytes can express PDGF-B, and OLDL and OVLDL enhance the expression; the monocyte conditioned media also can promote the 3HM-TdR incorpation into DNA of smooth muscle cells. Conclusions OLDL and OVLDL may play an important role in pathogenesis of atherosclerosis through stimulating the secreation of PDGF-B in monocytes, that promotes the proliferation of smooth muscle cells.