The volatile flavor compounds in Agaricus blazei fruit bodies and mycelia were analyzed by head space analysis GC-MS. 7 kinds of volatile flavor compounds were identified in fruit bodies, and 16 in mycelia. Benzaldehyde and benzyl alcohol are main compounds in fruit bodies, their contents are 43.20% and 28.98% respectively. Benzaldehyde is the main compound in the mycelia and its content is 38.50%. Benzaldehyde and benzyl alcohol are main volatile flavor compounds in Agaricus blazei.