Background: A biphasic agarose gel electrophoresis method using Chol/Trig ComboTM, which is based on the superimposing of separately-stained cholesterol and triglyceride gel images, can not only quantify the LDL-cholesterol(LDL-C) and HDL-cholesterol(HDL-C) levels but also recognize the entire lipoprotein patterns. Methods : We evaluated the analytical and clinical performances of Chol/Trig ComboTM agarose gel electrophoresis. The lipoprotein profiles of 256 Korean patients were tested by the Chol/Trig ComboTM agarose gel electrophoresis using Helena Epalyzer 2 and compared with laboratory chemistry analyzers. Results: Linearity of HDL-C and LDL-C by the Chol/Trig ComboTM electrophoresis in samples with total cholesterol concentration ranging from 8.3mg/dL to 295.5mg/dL yielded y1=1.1287y2-4.1631 in HDL-C(r=0.995), and y1=1.1287y2-4.1631 in LDL-C(r=0.999), respectively(y1 is the measured cholesterol concentration, y2 is the target cholesterol concentration calculated in diluted samples). Within-run and between-day coefficients of variation of HDL-C for 3 cholesterol levels(143, 171, 246 mg/dL) were below 4.2% and 8.8%, respectively; for LDL-C, below 3.3% and 5.8%, respectively. The Chol/Trig ComboTM electrophoresis cholesterol concentrations in LDL-C and HDL-C fractions on a set of 111 serum samples with cholesterol concentration ranging from 74 mg/dL to 356 mg/dL showed a good correlation to LDL-C (r=0.962) and HDL-C (r=0.914) levels obtained with laboratory chemistry analyzer. A total of 145 patients were classified by the Chol/Trig ComboTM electrophoresis according to WHO hyperlipidemia patterns as follows: Type I (n=100), Type IIa (n=17), Type IIb (n=5), and Type IV (n=23). Modified LDL was detected in 19.0% of Type I, 35.3% of Type IIa, 40.0% of Type IIb, and 60.9% of Type IV patterns. Conclusion : These results suggest the Chol/Trig ComboTM agarose gel electrophoresis may be an useful alternative for quantification of lipoprotein subfraction and for classification of hyperlipidemia patterns. Further study is required to evaluate whether modified LDL based on Chol/Trig ComboTM agarose gel electrophoresis may be useful as an indicator of risk for coronary artery disease.