Amino acids have the role in the process of proteins synthesis. They are an essential source of nitrogen atoms that have a role in the pathways of synthetic reaction pathways. The carbon skeletons of the amino acids are the source of energy in addition to their role as precursors in the paths of interactions. The amino acids analysis for the brain of the quail bird in different stage of de-velopment (10-16 days of incubation) in addition to the hatching stage (17th day) and the adult. Materials and Methods: Amino Acids Analysis The amino acids were separated from the embryos and adult brains of the quail bird Coturnix coturnix and were diagnosed based on standard amino acids, using high perfor-mance liquid chromatographic device (H.P.L.C.). Results: The results revealed that there are 16 amino acid: Aspartic acid, Glutamine, Ser-ine, Histidine, Threonine, Glycine, Arginine, Alanine, Tyrosine, Cysteine, Va-linine, Methionine, Isoleucine, Phenylalanine , Lysine, and the highest concen-tration of amino acid at age of [(13,13) days of incubation, adult, (13, 13, 16) days of incubation, adult, (13) days of incubation, adult, (13, 13, 11, 13, 13) days of incubation, adult, (13) days of incubation] respectively and the low concen-tration at age of [(14, 12, 10, 10,12,10,10,10,10, 14, 12, 12, 15, 10, 14, 10) days of incubation respectively]. Conclusions: It concluded from this that there was found 16 amino acid that were analyzed in the brains of the quail embryos at the stage (10-16) days of incubation and hatching stage (17) days of incubation and adult (Asp, Glu, Ser, His, Thr, Gly, Arg, Aln, Tyr, Cys, Val, Met, Ili, Leu, Phe, Lys, and Lys) the highest concentration of aging (13, 13, adult, 13, 13, 16, adult, 13, 13, 11, 13, 13, adult and 13) respectively, and less concentrated in ages (14, 12, 10, 10, 10, 10, 14, 12, 12, 15 10, 14, 10) days of incubation, respectively.