An amino acid composition is provided that can promote fat burning, improve endurance, and reduce fatigue during, for example, marathons, and that can lessen obesity and increase stress resistance. The amino acid composition comprises 3.0 to 10.0 mass parts of aspartic acid, 2.5 to 9.0 mass parts of threonine, 2.0 to 9.5 mass parts of serine, 12.0 to 40.0 mass parts of glutamic acid, 7.0 to 20.0 mass parts of proline, 0.5 to 4.5 mass parts of glycine, 1.0 to 4.5 mass parts of alanine, 3.0 to 12.0 mass parts of valine, 0.1 to 0.8 mass part of cystine, 1.5 to 5.0 mass parts of methionine, 2.0 to 8.0 mass parts of isoleucine, 5.0 to 15.0 mass parts of leucine, 3.0 to 10.0 mass parts of tyrosine, 3.0 to 10.0 mass parts of phenylalanine, 4.0 to 15.0 mass parts of lysine, 0.8 to 4.0 mass parts of tryptophan, 1.5 to 5.0 mass parts of histidine, and 2.0 to 6.0 mass parts of arginine, wherein the total amount of these amino acids is 100 mass parts.
