Aim To observe the effects of cholesterol-rich lipoproteins [β-very low density lipoprotein (β-VLDL), normal low density lipoprotein (n-LDL)and oxidized low density lipoprotein(ox-LDL)] on lipid accumulation in smooth muscle cells (SMCs) and to explore its mechanism . Methods β-VLDL, n-LDL or ox-LDL was incubated with rabbit aortic SMCs for 48 hours, total cholesterol(TC)and triglyceride(TG)of the cells were extracted and determined. The increasing concentrations of lactoferrin (specific ligand of LDL receptor-related protein ,LRP) were added withβ-VLDL, n-LDL or ox-LDL, respectively, in the culture and TC and TG of the SMCs were determined as above. SMCs were incubated at 4℃ in M199 containing different concentrations of unlabeled lactoferrin and FITC-β-VLDL, FITC-n-LDL or FITC-ox-LDL, respectively, for 4 hours. The cell surface bound lipoproteins were determined by fluorospectrometry. Results β-VLDL, n-LDL and ox-LDL can all increase TC and TG accumulation in SMCs. More TC and TG were accumulated withβ-VLDL as compared with n-LDL or ox-LDL. The effects can be inhibited by lactoferrin. Moreover, lactoferrin competed with FITC-β-VLDL, FITC-n-LDL or FITC-ox-LDL on binding to SMCs. Conclusion β-VLDL, n-LDL and ox-LDL may contribute to lipid accumulation in SMCs by LRP mediated pathway.