As a part of research for clarifying the genetic composition of Korean population, phenotypes and allele frequencies of Apo A-IV and Apo E in human plasma have been studied using polyacrylamide gel isoelectric focusing and immunoblotting techniques. Blood samples were obtained from healthy individuals living in Seoul, Kangnung and Cheju, Korea. Two phenotypes of Apo A-IV controlled by two alleles were appeared in Korean population. The calculated allele frequencies of Apo A-IV*1 and Apo A-IV*2 were 0.9851 and 0.0149, respectively. There were four phenotypes for Apo E in Korean population. On the basis of 3 alleles for Apo E, allele frequencies of Apo E*2, Apo E*3 and Apo E*4 were 0.0054, 0.8216, and 0.1730, respectively.