Volatile aroma concentrates of four oyster mushrooms cultivated in Korea were obtained by the simultaneous distillation-extraction method. The volatile components were identified by the combined capillary gas chromatography-mass spectrometry and compared with the of retention data on GC of those authentic compounds. About 54 volatile compounds were identified in each of the four edible oyster mushrooms. The main compounds in Pleurotus ostreatus ASI 201 were 1-octen-3-ol, 3-octanone, 3-octanol, in Pleurotus sajor-caju, 1-octen-3-ol, 3-octanone, 1,5-octadien-3-one, 3-octanol, in Pleurotus florida-ostreatus-ostreatus, 1-octen-3-ol, n-hexanol, 3-octanone, 3-octanol, phenol, and in Pleurotus ostreatus (Ae-Neutari), 1-octen-3-ol, n-pentanal, n-hexanol, n-pentanol, 3-octanone, 3-octanol, 1,5-octadien-3-one, respectively. The mushrooms worked were rich in an alcohols and carbonyl compounds containing $C_8$ compounds. The peak area ratio of $C_8$ compounds in aroma concentrates were 56.60% in Pleurotus ostreatus ASI 201, 72.46% in Pleurotus sajor-caju, 54.84% in Pleurotus florida-ostreatus-ostreatus and 35.85% in Pleurotus ostreatus (Ae-Neutari ), respectively.