Aim To study the expression of macrophage inflammatery protein (MIP) 1α in atherosclerotic lesions and to examine the effects of native and oxidized low density (LDL, oxLDL) and very low density lipoproteins (VLDL,ox VLDL) on the expression of MIP 1α in human peripheral blood monocytes. Methods The expression of MIP 1α mRNA in dietary atherosclerotic lesions in rabbits was detected by in situ hybridization. The effects of LDL, ox LDL, VLDL and ox VLDL on the expression of MIP 1α mRNA and protein in human blood monocytes were determined by RT PCR and cell ELISA respectively. Results In situ hybridization showed that the cytoplasm of the foam cells was stained brownish purple, and the lipid droplets in the cytoplasm were not stained so that the whole foam cell area looked like a brownish purple network. The cytoplasm of endothelial cells was stained as well. RT PCR demonstrated that ox LDL and ox VLDL induced a 2.4 fold and a 1.6 fold increase in MIP 1α mRNA expression in human blood monocytes respectively compared with the control group, and cell ELISA also showed that ox LDL and ox VLDL induced a 2.3 fold and a 2.0 fold increase in MIP 1α protein expression in monocytes respectively, while LDL and VLDL didn't. Conclusions The Foam cells and endothelials in the atherosclerotic plaques can express MIP 1α. ox LDL and ox VLDL might be able to induce increased expression of MIP 1a mRNA and protein in human blood monocytes, and could, therefore, enhance the atherogenesis through increased recruitment of more and more monocytes into the arterial intima.