摘要:In this study, grey oyster mushroom (Pleurotus pulmonarius) was cultivated in indoor controlled environment to seeking out the possible risks of contamination and ways of treatment to avoid the contamination. For this, mushroom was cultivated in providing artificial humidifying and ventilation system to ensure optimum humidity (80-90%) and fresh air recirculation in different ways of treatment. The ways of treatment were included as in position of humidifier, frequency of humidifying, plastic cork of bags opening part and cleaning of humidifier water container. Maximum percentages of bag contamination (2.5-25.30%), cap contamination (5.6-30.75%), stalk contamination (4.75-23.25%) and root contamination (2.6-18.45%) were found in front to front humidifier position, long humidifying with long interval frequency, without plastic cork, without cleaning and bi-monthly cleaning of humidifier water container treatment but no diseases and pest infection was found. Whereas, very low percentages of contamination (0.1-0.5%) were found in surrounding humidifying position, short humidifying duration with short interval frequency, with plastic cork and weekly cleaning of humidifier water container treatment.