Aim To well understand the mechanism of native and oxidized very low density lipoprotein (VLDL) and OVLDL) in the atherogenesis, we investigated the influences of VLDL and OVLDL on intracellular free calcium concentration ([Ca2+]i).Methods Very low density lipoprotein was isolated from normal blood donors by density gradient ultracentrifugation, and oxidized by CuCI2 with a final concentration of 10 μmol/L. Rabbit peritoneal exudate macrophages were collected. For determination of [Ca2+]i , fura-2 fluorescence and microfluorimetry were used.Results Both VLDL and OVLDL significantly increased [Ca2+]i in macrophages. VLDL induced an increase of 57% in [Ca2+]i , where as OVLDL induced an increase of 115% in [Ca2+]i.Conclusions It suggests that VLDL and OVLDL induce many biological functions by stimulating increase of [Ca2+]i in macrophages, but the latter are more stronger than the former. This corresponds to the fact that OVLDL induces stronger biological functions including migration and secreting cytokines.