Total content of amino acids and oligopeptides in sake was determined by the ninhydrin method. The amino acid content was determined only by a modified method that ninhydrin solution containing Mc'Ilvaine's buffer at pH 4.0 was used and reaction solution was heated for 5 min. The peptide content was estimated from the difference between the data obtained as above and those obtained by using acetate buffer at pH 5.0 and heating for 20 min. Recovery of added peptide in sake was ranged from 83.0 to 91. 0% and the peptide contents of 20 brands of commercial sake were in the range of 3. 53 to 7. 50 m molef 1. The results of these methods correlated well (γ=0. 9535, n=8) with those of a hydrolysis method.