The edible mushrooms are very well known according their nutritional and medical value. The human nutrition enriched by growing mushrooms is recommended thanks to their very positive influence on the different aspect of metabolism. However, the technology of cultivation of growing mushrooms include a chemical treatment of the growing houses mainly by fungicides, as the fungal diseases are most dangerous for the mushroom crop.

Those treatment may have a serious influence on the quality of fruit bodies.

On the other hand, the presented mycopopulation in the compost for mushroom growing had not been often the subject of investigation. As the fungicides treatment can be successful only in the case that mycopopulation is well known, we had started with our study.

The compost samples were taken during the growing circle of A.bisporus in the commercial mushroom farm. After 7 days incubation of the samples on the sterile, wet filter paper and Malt agar as well, the isolation and determination of mikrofungi were done. Next species were identified: Trichodermaharisianum, Mucor sp., Rhizopus sp., Epicoccumpurpurascens, Trichoteciumroseum, Chromelosporium state of Peziza ostracoderma and Doratomices stemonitis. All of the identified species, except Chromelosporium spp. are very often and their isolation from ground, air, water, live and death plant material atc., can be done routinely. However, the Chromelosporium sp. According the literature data, is specify for the Agaricus bisporus growing rooms.