Amino acids in fifteen species of edible mushrooms were analyzed by Paper-chromatography. The results as follows : 1. The types of amino acids found in a species of mushroom were from four to thirteen. The mushrooms examined five were not identified. 2. Amino acids in the majority of the mushrooms examined were nine, i.e. DL-Alanine, DL-Methionine, L-Arginine, L-Aspartic acid, DL-Serine, L-Phenylalanine, Histamine, DL-iso-Leucine, D-Glucosamine. DL-Threonine, L-Lysine, Phenylalanine, Citurulline, Hydroxy-L-Proline in Agaricaceae, especially Tryptophane and Histamin were peculiar to Agaricaceae, and Alanine and Cistine in Hypholoma lateritum(SCHAFF) SCHROT. 3. It seems that the factor which determines the taste of each mushrooms depends upon hte various configuration the amino acids.