Hyperlipoproteinemia phenotyping has been re-evaluated by an improved agarose gel electrophoretic test. Eight varieties of serum lipoprotein electrophoretic patterns are demonstrated, two from clinically normal normolipidemic subjects and six from patients with hyperlipoproteinemia that include the phenotypes 1, 2a, 2b, 3, 4, and 5. The sharp delineation of the lipoprotein patterns achieved by this technique facilitates the differentiation and identifcation of the lipoprotein phenotypes. Furthermore, the lipoprotein patterns can be visually evaluated, correlated with their corresponding serum lipid values, and associated with the clinical and hereditary features of the hyperlipoproteinemia phenotypes. This test system can also be used in clinical trials and epidemiological studies.