Quantitative analysis was achieved by gas-liquid chromatographic method (GLC) with a single column system of OV-17 for 16 of protein amino acids in mushroom (agaricus bisporus). The quantities of protein amino acids in mushroom were determined $48.32{\sim}255.94mg%$ alanine, $108.6F{\sim}364.82mg%$ glycine, $124.30{\sim}314.17mg%$ Valine, $32.99{\sim}418.79mg%$ leucine and isoleucine, $151.78{\sim}669.07mg%$ threonine, $88.12{\sim}4F6.3Fmg%$ Serine, $21.9F{\sim}114.94mg%$ Hydroxyproline, $20.F4{\sim}174.63mg%$ proline, $34.52{\sim}173.59mg%$ Methionine, $225.25{\sim}1417.61mg%$ Aspartic Acid, $10F.00{\sim}392.17mg%$ Phenylalanine, $12F.46{\sim}535.65mg%$ Glutamic Acid and Lysine, Tyrosine in trace amount.