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.