Triglyceride - rich hpoprotein (TRL) remnants have been imphcated by both clinical and laboratory studies in the pathogenesis of atheroselerosis and thrombosis. We use an new immunoseparation method, provided by Japan Immunoresearch Laboratories, to determine the remnant - hke particles(RLP) of hpeproteins. Isolation of RLP from serum is achieved using an immunoaffmity gel containing specific anti - human apoA- I and apoB- 100 (JI - H) monoelonal antibodies, where the former recognizes HDL and newly secreted apoA - I - containing chylomicrons, the latter recognizes LDL and majority of VLDL. As a result of the specificity of the JI - H antibody, the majority of the apoB - 48 - containing chylomicrons, and certain apoE - enriched apoB - 100 - containing VLDL axe not recognized. These lipoproteins are not captured by the immunoaffinity gel and are thus isolated in the unbound RLP fraction,which is predominantly made up of TRL having remnant - hke properties. The components of the unbounded fraction axe the remnants of CM and VLDLs, verified by ultracentrifugation and lipoproteins electrophoresis in agarose gels. We established a convenient approach to measure RLP- cholesterol on the Hitachi 7150 biochemical analyser.The within- run and run - to- run imprecision (CV) of the assay was 2.75% and 11.48% respectively. The linear of the RLP- c in our assay was 0 - 180 mg/dl. We chose 30 normal lipids level for the control group ( 15 male & 15 female), the median fasting serum RLP - c concentration was 8.12 ± 4.88 mg/dl. We fred that RLP - c concentration were signficantly correlated with TG, VLDL - c, HDL -c & apoE( r = 0.765,0.511, - 0. 378,0.241 respectively, P < 0.01 ) ; and no signficant correlation was subsequently observed between RLP- c and LDL- c. In our study, the median fasting RLP- c concentration were significantly higher in 91 patients with coronary artery disease (CAD),in 15 patients with non- insulin dependent diabetes meUitus (DM),and in 45 patients undergoing hemodialysis with end - stage retinal disease