We have recently developed an HPLC method able to separate five lipoproteins (HDL, LDL, IDL, VLDL and chylomicron) followed by cholesterol measurement on each lipoprotein. As an application of this method, this study focused on analyses of triglyceride (TG)-rich lipoproteins, one of risk factor for atherosclerosis. The appearance of midband on electrophoresis is conceivably implicated in atherogenesis. The present study revealed that cholesterol levels in VLDL, IDL and LDL were significantly higher in midband-positive sera than negative sera. Cholesterol levels in remnant-like proteins, another atherogenic indicator, were significantly related to those in VLDL and Chylomicron measured by the present HPLC method. In conclusion, this novel HPLC method can provide valuable information for analyses on TG-rich lipoproteins.