The frequencies of the major apolipoprotein E(apo E) phenotypes in 65 normal, 426 hyperlipidemics, and 92 familial hypercholesterolemic Japanese subjects (FH) were studied, and features of hyperlipidemia compared between non-FH hyperlipidemia and FH. The frequencies of apo E phenotypes 3/3, 4/3, 3/2, 4/4 were almost the same in normal, non-FH hyperlipidemic, and FH subjects. The incidence of apo E7 was about 0.5% of total subjects. In type IV and V hyperlipidemias, incidence of E4/3 was higher than in any other hyperlipidemia. Incidence of E3/2 was also high in types III and V. In type II non-FH hyperlipidemia, incidence of E3/2 in type IIb was higher than in type IIa. VLDL-triglyceride, VLDL-cholesterol, apo C-II, apo C-III, and apo E levels were higher in E3/2 than in E3/3. But, in type IIa FH and type IIb FH, the incidence of E3/2 was the same, and lipid and apolipoprotein levels between 3/2 and 3/3 in FH were the same. These results indicate that allele epsilon 2 may be involved in the retention of VLDL or IDL, but not in FH.