Prochloraz of fungicide was applied on Mycogone perniciosa causing wet bubble in cultivated mushroom, Agaricus bisporus. In vitro, Prochloraz was an excellent fungicide on two strains of Mycogone, tolerant and non-tolerant to Benomyl, respectively. At the low dosage, Prochloraz more inhibited mycelial growth of mushrooms than Benomyl. At the higher dosage, Benomyl more inhibited the mycelial growth than prochloraz. The higher yield of sporophore of the mushroom with low inferction rate was abtained from several trial of Prochloraz. Prochloroz was concluded to be effective fungicide on Mycogone perniciosa on Agaricus cultivation.