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(S_CHAFF) S_CHROT. 3. It seems that the factor which determines the taste of each mushrooms depends upon the various configuration the amino acids.