Koji (Aspergillus oryzae) is used to ferment crude cereals of wheat to make a traditional alcoholic drink called Makkolli and industrial materials. It’s quality varies depending on the wheat quality. Four domestic wheat varieties (Kosomil, Jokyungmil, Geumgangmil, Baegjungmil) were characterized. They were found similar in pH (6.02 to 6.08) and total acid (0.105 to 0.120%) contents. However, amino acid content of Gemgangmil was the highest (4.46%) and that of Baegjungmil was the lowest (3.72%). The total bacillus number was highest in Kosomil (333×103CFU/ml) and lowest in Gemgangmil (60×103CFU/ml). On the other hand, the fungus number was 47×105CFU/ml in Gemgangmil and the other varieties had similar quantity. The content of Alpha-amlyase was the highest (500.01unit/g) in Kosomil followed by Jokyungmil and Gemgangmil, and the lowest was in Baegjungmil (353.32unit/g). The content of Glucoamlyase was the highest in Geumgangmil (5105.0unit/g) followed by Jokyungmil and Kosomil, and the lowest was in Baegjungmil (3880.0unit/g). Acid protease was the highest in Kosomil (3515.15unit/g) followed by Geumgangmil and Baegjungmil, and the lowest in Jokyungmil (1280.5unit/g). From the result, Koji made from Kosomil was found to be of superior quality.