By combination of laser scanning confocal microscopy(LSCM) and the highly sensitive fluorescent dyes BODIPY FL-LDL and DiI-AcLDL, it is possible that activities of both LDL and scavenger receptors in a single cell can be measured simultaneously and quantitatively. For example, in C57BL/6J macrophage, it was found that the cells were incubated for 5 h at 37℃ with 5 mg/L DiI-AcLDL and 5 mg/L BODIPY FL-LDL resulted in excellent color imaging under LSCM, the LDL receptor with green and scavenger receptor with red. The high selectivity and visulization of this method provide detailed information on the localization and activity of both receptors in a single macrophage. The rapidity and accuracy of this assay allows its application for studying receptor-mediated lipoprotein uptake.