Changes in taste components of Backilju, an traditional alcoholic beverage of Korea, were investigated. Ethanol(17%) was the most abundant, and then isoamylalcohol(23mg%) and methanol(8mg%) were also detected in a small amount in Backilju. Major non-volatile organic acids were lactic and malic acid, followed by citric, fumaric and succinic acid. Arginine, phenylalanine and glutamic acid were major free amino acids and essential amino acid content was 230∼560 mg%, which was 45∼48% of total free amino acids. The major fatty acid of total lipid was palmitic acid(37∼43%). It has been found that the Backilju contained more free amino acids and alcohols than other Korean Yokjus.