Sodam oyster mushroom(Pleurotus ostreatus were bred in Mushroom Research Institute, Gyonggi Province A.R.E.S in 2002. Sodam oyster mushroom were bred and cultivated one after mating single spores collected from Aenutari 1-ho and Suhan 1-ho. The major characteristics of the mushroom are showing a lot of pinheadings, the graycolored and shallow cornhead-shaped pileus. Around 20 days at 20 were required for incubation of Sodam and the yield was shown high by 148.2g/bottle. As the activity of hypha is so strong, the proper time of pinheading is demanded.