In analysis of inorganic components of Miscanthus sinensis Andersson var. sinensist, Phosphate increased with theprogress of growing stage. in other way potassium, calcium and magnesium was inclined to decrease. The total nitrogen contentin the Miscanthus sinensis Andersson var. sinensist was increased until second age cultivated stage, but in its third year, it wasdecreased apparently. In other way the total carbon content of Miscanthus sinensis was not changed until second year cultivation.But rapid increasing was happen in its third year cultivation stage. 3 year cultivated Miscanthus sinensis Andersson var. sinensistwhich has a plentiful carbon source can be used as a good culture media source for the formation of mushroom’s fruit body.When rice bran added at the amount of 20% to the keep in 65% moisture Miscanthus sinensis Andersson var. sinensist, thefermentation of culture material was well done and the temperature of 50~55^oC fittest for thermophilic microorganism growthwas maintained for 5 days from 5 days after treatment. Rice bran 20% added to the Miscanthus sinensis Andersson var. sinensistwas the fittest fermentation culture media for the Pleurotus ostreatus vinyl-bag type cultivation. When Pleurotus ostreatus wascultivated in this culture media, the yield was increased by 60% than whole Miscanthus sinensis Andersson var. sinensistcontaining culture media. The fermentation Miscanthus sinensis Andersson var. sinensist culture media could be substituted by20% the sawdust in existing culture media(sawdust 50%+cottonseed bark 30%+cottonseed meal 20%)