Ten-day-old fungal materials of P. myriotylum in PDB were amended with 0, 40, 60 and 80 μg/ml E. adenophorum oil extracts were used for the TEM observation to study the mode of action of oil extracts . The mycelium pellets were treated with 2.5% glutaraldehyde at 4°C, followed by rinsing with 0.1 M phosphate buffer (pH 7.2) and fixed with 1% w/v osmium tetraoxide solution. The fixed samples were rinsed with the same buffer three times. Afterwards, the samples were dehydrated using a series of ethanol solutions in the order of concentration 30, 50, 70, 80, 90, 95 and 100%. After dehydrating and embedding in Spurr’s resin, thin sections were cut and double-stained with uranyl acetate and lead citrate. The grids were examined with a New Bio-TEM H-7500 transmission electron microscope (Hitachi Company, Japan).