Abstract : The amino acid compositions of Spent coffee, green coffee beans, and medium roast coffee from robusta Coffee, cultivated in Saba Yoi District, Songkhla Province, Thailand, were investigated. The impact of the roasting process on the amino acid profiles of robusta coffee samples was analyzed using an amino acid analyzer. Upon hydrolysis, the amino acids demonstrated distinct thermal stabilities; for instance, Aspartic acid (Asp), Tyrosine (Tyr), Valine (Val), Leucine (Leu), Phenylalanine (Phe), Glycine (Gly), Histidine (His), and Alanine (Ala) exhibited stability across all analytical temperatures. During the roasting of coffee beans, there was an observed increase in the quantities of the amino acids glutamate, glycine, and leucine. Conversely, certain amino acids, including Arginine (Arg), Lysine (Lys), and Serine (Ser), exhibited a significant decrease in quantity as a result of the roasting process. This indicates that the roasting of Coffea robusta beans has discernible effects on the amino acid composition, with some amino acids being more stable while others undergo changes in their concentrations during the roasting procedure.